K-State Research and Extension Horticulture Newsletter
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Fruit: Be on the Lookout for Peach Leaf Curl and Plum Pocket

5/2/2017

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​Peach leaf curl is a fungus disease that causes developing peach leaves to become puckered and distorted and show a reddish-green hue. A similar disease called plum pocket may develop on American and sand hill plums. Plum pocket results in formation of distorted, light green, bladder-shaped fruit. Asian and European plums are not susceptible to the local strain of plum pocket. Unfortunately, it is too late to control any of these diseases with fungicides this year.
        
Trees that are severely infected with peach leaf curl are likely to lose many leaves. If trees are healthy, new leaves will grow. Indicators of a healthy tree are large, deep green leaves and last year's growth being at least 18 to 24 inches long. If these tree vigor indicators are not present, especially if there was only 12 inches or less of growth last year, then a fertilizer application would be helpful.
        
The fertilizer should be spread on the soil under the branch area. Apply 1 and 1/3 to 2 cups of a 13-13-13 fertilizer under the branch area. If a soil test indicates that only nitrogen is needed, use 1/3 to 1½ cups of nitrate of soda (16-0-0) instead of the 13-13-13. You may also substitute a high nitrogen fertilizer such as a 27-3-4, 30-5-4 or something similar for the 13-13-13, but use only half the amount used for nitrate of soda. The sooner fertilizer is applied, the more immediate benefit it will have in promoting new leaf growth. Both peach leaf curl and plum pocket can be controlled with a single fungicide application applied this fall after leaf drop or early next spring before bud swell.
        
Effective fungicides include Bordeaux mixture and chlorothalonil (Bravo, Daconil and others). Be sure to cover the entire tree including the bark and trunk. (Ward Upham)

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Fruit: Frost Tolerance of Apricots and Peaches

3/14/2017

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Growers of apricots and peaches often wonder at what temperature fruit buds are killed especially in years where we have an early spring.  These two tree fruits bloom very early and are often caught by a late frost. The following will give you some guidelines but remember that the actual damage is going to be influenced by the weather before the temperature drops. An extended warm spell before the cold snap may result in more damage due to a loss in cold hardiness. The stages listed are for the fruit buds.
 
Apricot
Stage                10% Kill (°F)           90% Kill (°F)
First white             24                         14
First Bloom           25                         19
Full Bloom             27                        22
In the Shuck          27                         24
Green Fruit           28                          25

Peach
Stage                10% Kill (°F)           90% Kill (°F)
Swollen bud        18                             2
Half-inch green  23                            5
Pink                        25                            18
Bloom                    27                            24
Petal fall               28                            25
Fruit set                28                            25

 
To check for low temperature injury to fruit buds or blossoms, use a sharp knife and cut them in half longitudinally (from top to bottom). If the tiny seed in the center is white to cream color no damage has been done. But if the seed in several buds or blossoms is dark brown or black, it has been killed.
 
It is possible to give some protection to blossoms from freezing by covering the tree with a bed spread, blanket or similar fabric. Old-fashioned Christmas lights distributed around the tree will help to give additional protection. The newer, smaller Christmas lights do not give off enough heat and are not recommended. Of course the practicality of this method of protection depends upon the size and number of trees.
 
Sprinkling the tree with water throughout the freezing period can also protect the blossoms. Sprinklers should be started before the temperature drops to freezing to be sure ice does not block the garden hose or water line. Continue until the temperature warms. With this protection method, there is the potential of creating an ice storm. If temperatures remain below freezing for several hours, ice will accumulate on the branches and limbs. The weight from the ice may cause branches and limbs to break causing severe, and possibly permanent, damage to the tree structure. Also, if water drainage from the soil is slow and the water displaces oxygen from the roots, damage to trees may result. (Ward Upham)

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Horticulture Newsletter 2017, No. 6

2/7/2017

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Video of the Week:
Prairie Flowers: Hardy for Kansas

Fruit:
Approaching Time for Peach Leaf Curl Control

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​If you have ever seen emerging peach leaves that are puckered, swollen, distorted and reddish-green color, you have seen peach leaf curl. Uncontrolled, this disease can severely weaken trees due to untimely leaf drop when leaves unfurl in the spring. Fortunately, peach leaf curl is not that difficult to control if the spray is applied early enough. However, by the time you see symptoms, it is much too late. As a matter of fact, fungicides are ineffective if applied after buds begin to swell.
       
Don't spray when temperatures are below 40 degrees or will fall below freezing before the spray dries. Usually we can wait until March to spray but an extended warm period in February that encourages early bud swell may require spraying in late February. Though peach leaf curl can be controlled by a single fungicide application either in the fall after leaf drop, it is more commonly controlled in the spring.
       
There are several fungicides labeled for this disease including chlorothalonil (Ortho Garden Disease Control, Fertilome Broad Spectrum Fungicide, GardenTech Fungicide Disease Control and Daconil). Thoroughly cover the entire tree during application. Note that it is much easier to achieve good spray coverage if the tree is pruned before spraying. (Ward Upham) 

Pruning Overgrown Apple Trees

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​Apple trees that are not pruned for several years will often produce so many branches that little energy is left for fruit production. Overgrown apple trees are also difficult to harvest and spray. Gardeners who have such a tree are often at a loss as to how to get it back in shape.
       
Often the best recommendation for such a tree is to make one pruning cut at ground level and start over with a new tree. However, trees may have sentimental value that will make revitalization worth the time and effort. Realize that this will be a multi-year process because no more than 30 percent of the tree should be removed in one year. Here are some steps to follow:
       
1. Remove all dead wood. This does not count toward the 30 percent.
2. Remove suckers from the base of the tree.
3. Choose approximately six of the best branches to keep as scaffold branches. Remove all others.
       
Branches should be cut flush to the branch collar. The collar is the natural swelling that occurs where a branch connects to the trunk or to a larger branch. Removing the collar would leave a larger wound that would take additional time to heal. Do not paint wounds. Wounds heal more quickly if left open. Candidates for removal include branches with narrow crotch angles, which are more likely to break in wind and ice storms, and those that cross branches you will save. This may be all that is possible the first year if the 30 percent threshold has been reached.
       
4. Thin the branches on each scaffold branch. Remove crowded branches to open up the tree to light and allow humidity to escape. Shorten each scaffold branch by cutting back to a side branch. When you are through, the tree should have enough wood removed so that a softball can be thrown through the tree.
       
Severe pruning often will cause an apple tree to produce vigorous side shoots from the trunk called water sprouts. Main branches will also produce suckers that grow straight up. The suckers and water sprouts should be removed throughout the growing season so the center of the tree stays open. Removing water sprouts and suckers is the most time consuming and difficult practice necessary to bring an overgrown apple back into shape. (Ward Upham)

Pruning Fruit Trees

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Fruit trees can be pruned from now through March as long as the wood isn’t frozen. Following are some general recommendations on pruning mature fruit trees followed by more specific instructions on each species. If you have young fruit trees, see the accompanying article in this newsletter.
 
General Recommendations
- Take out broken, damaged or diseased branches
- If two branches form a narrow angle, prune one out. Narrow angles are weak angles and tend to break during wind or ice storms.
- Take out all suckers. Suckers are branches that grow straight up.  They may originate from the trunk or from major branches
- If two branches cross and rub against one another, one should be taken out.
- Cut back or remove branches that are so low they interfere with harvest or pruning. If cutting back a branch, always cut back to another branch or a bud. Do not leave a stub.
- Cut back branches to reduce the total size of the tree, if necessary.
- Thin branches on the interior of the tree.
 
Follow the steps above in order but stop if you reach 30% of the tree. For a short video on pruning, click here.
 
Specific Instructions
Peach and Nectarine: Peach and nectarine require more pruning than any other fruit trees because they bear fruit on growth from the previous year. Not pruning results in fruit being borne further and further from the center of the tree allowing a heavy fruit crop to break major branches due to the weight of the fruit. Prune long branches back to a shorter side branch
       
Apple: Apples tend to become overgrown if not pruned regularly. Wind storms and ice storms are then more likely to cause damage. Also, trees that are not pruned often become biennial bearers. In other words, they bear a huge crop one year and none the next. Biennial bearing is caused by too many fruit on the tree. Though pruning helps, fruit often needs to be thinned as well. The goal is an apple about every 4 inches. Spacing can vary as long as the average is about every 4 inches.
       
Cherry, Pear, Plum: Light pruning is usually all that is needed. Simply remove branches that are causing or will cause a problem according to the general recommendations above. (Ward Upham)

Pruning Young Fruit Trees

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​Young fruit trees should be pruned to begin developing a strong structure of the main or scaffold limbs. This will help prevent limb breakage over the years when the scaffolds carry a heavy fruit load. Apple, apricot, cherry, plum and pear trees generally are trained using the central leader system. The growth pattern for these trees is for a center branch to be dominant and to grow straight up. Peach and nectarine trees are normally pruned using the open center method because they do not have a strong tendency for one shoot or branch to dominate the growth of other shoots or branches. In this system, the tree is pruned to a vase-like pattern with no central leader.
       
Regardless of the system used, the three to four scaffold branches should:
        • Be no lower than 18 inches from the ground. This makes it easier to prune and harvest the tree once it matures.
        • Form wide angles (about 60 to 80 degrees) with the trunk. Wide angles are much stronger than narrow angles and are less likely to break under wind or ice loads.
        • Be distributed on different sides of the tree for good balance.
        • Be spaced about 6 to 10 inches apart on the trunk with no branch directly opposite or
below another. (Ward Upham)

Flowers:
Handling Tips for Valentine's Day Roses

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If you are fortunate enough to receive roses from a loved one this Valentine's Day, follow these guidelines to help extend the life of your flowers.
 
For floral arrangements:
        1) Keep the vase filled or floral foam soaked with warm water. Add fresh, warm water daily. If the water turns cloudy, replace it immediately. If possible, recut stems by removing one to two inches with a sharp knife. Do this under water. This allows the stems to draw in water instead of air.
        2) Keep flowers in a cool spot (65 to 72 degrees Fahrenheit), away from direct sunlight, heating or cooling vents, directly under ceiling fans, or near radiators.
        3) If a rose starts to wilt, remove it from the arrangement, and recut the stem under water. Submerge the entire rose in warm water. The rose should revive in one to two hours.
 
For loose stems:
        1) If you can't get your flowers in a flower food solution right away, keep them in a cool place.
     2) Fill a clean, deep vase with water and add the flower food obtained from your florist. Be sure to follow the directions on the package.
        3) Remove leaves that will be below the waterline. Leaves in water will promote bacterial growth.
      4) Recut stems under water with a sharp knife and place the flowers in the vase solution you've prepared. (Ward Upham)

Pests:
Check Plants for Scale Insects

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The dormant season is a good time to check woody plants for scale insect infestations. This time of year, deciduous plants do not have leaves, so scale is more easily seen.
       
If an infestation is detected, make plans to apply a dormant oil for control by March 1. Be sure the temperature is 40 degrees or above before spraying. Scale insects are easily overlooked because they are small and immobile most of their lives and they do not resemble most other insects.  Many of them resemble small shells that are oval or circular, but some have more unusual shapes like oyster shells. Coloring varies, but can include white, tan, and brown.
       
Plants that should be inspected for scales include apples, pears, other fruit trees, bush fruits, lilac, crabapple, oak, ash, elm, lilac, maple, linden, arborvitae, juniper, pine, spruce and yew. Manhattan euonymus, a broadleaf evergreen, is especially noted for having scale problems.
       
Plants are not harmed if only a few scales are present. But scale population can increase dramatically during the growing season. Heavy scale infestations can damage fruit crops, destroy branches and kill entire plants. (Ward Upham)

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Horticulture Newsletter 2016, No. 31

8/2/2016

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Video of the Week:
When is Cantaloupe Ripe on the Vine?

Upcoming Events:

August 4         Kansas Turfgrass Field Day, Manhattan
 https://turffieldday.eventbrite.com
 The field day program is designed for all segments of the turf industry - lawn care, athletic fields, golf courses, and grounds maintenance. Included on the program are research presentations, problem diagnosis, commercial exhibitors, and equipment displays. There will be time to see current research, talk to the experts and get answers to your questions. Pesticide recertification credit in 3B is available and 0.25 GCSAA education points
 
August 15       K-State Vegetable Research Field Day, Olathe
http://hnr.k-state.edu/events/2016%20GG%20Vegetable%20Research%20Tour.pdf

Fruit:
When Are Apples Ready to Pick?

apples
Apples mature over a long period of time depending on variety. Some varieties such as Lodi can mature in July and others as late as October.  Here are some guides to help you decide when to pick your apples.
 
Color change: As apples mature, the skin color in areas of the stem and the calyx basin at the bottom of the apple turns from an immature green to a light-yellow color. Some apples will develop a red skin color before they are ripe, so this is not a reliable indication of maturity.
 
Flavor: This is a good guide if you are familiar with the apples you have and know how they should taste. Even if you do not know the characteristic flavor of the kind of apple you have, you can still sample slices of a few apples and decide if they have a sweet flavor. If they are not ready to harvest, they will taste starchy or immature. If apples have already fallen and taste a bit starchy, store them for a period to see if they become sweeter.
 
Flesh color: As apples mature and starches change to sugars, the flesh changes from very light green to white. When you cut a thin slice and hold it up to the light you can see the difference.
 
Days from bloom: The number of days from bloom is a reliable guide for general maturity time, but weather conditions will have some influence. Some kinds of apples and approximate days from bloom to maturity are Jonathan, 135, Delicious, 145, Golden Delicious, 145, and Winesap,155 days. This process may be slower than usual due to the cooler weather this year.
 
Seed color: The seeds of most apples change from light green to brown as the fruit ripens. This indicator should be combined with other changes since it is not absolute. The flavor of the apples, the change in color of the stem and calyx basins and flesh color are important in deciding if apples are ready to harvest. (Ward Upham)

Peaches; Pitburn and Split Pits

peach split pit
As fruit growers are harvesting peaches, some are noticing split pits and/or pitburn.
 
Pitburn is evidenced by brown or gray areas around the pit and is caused by high temperatures and rapid growth. It actually isn’t the high temperatures that injure the flesh directly but a lack of oxygen interfering with normal development.  Remember the very high temperatures we had earlier in the year?  Those high temperatures led to pit burning.
 
Split pits are also often the result of rapid growth and can be made worse with excessive thinning and/or irregular watering during the pit hardening stage. Such peaches are more likely to rot than those with intact pits.
 
There isn’t anything that can be done at this stage to help the peaches.  However, a good job of watering and avoiding overthinning can help prevent split pits in the future. Peaches with pitburn or split pits are safe to eat.  (Ward Upham)

Vegetables:
Fall Gardens

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This is the time of year we normally think of planting a fall garden. Crops that can be planted now include lettuce, radishes, spinach, and similar crops. There still is time to raise another crop of green beans along with some summer squash. If you can find plants, cabbage, broccoli and cauliflower can also mature during the fall season.

Planting a fall garden is just like planting a spring garden with some big advantages. You will find the weed pressure to be much less and insect problems may be far fewer than in a spring garden. Seeds will germinate rapidly, so you will have crops up and growing in just a few days – compared to several weeks in the spring.
 
There are a few drawbacks to fall gardening, and one of those is that you must provide regular, frequent watering (possibly daily) until the crops are up and growing. It is best to plant seeds deeper than you do for a spring garden because soil is cooler and moister down a little deeper.
 
As far as soil preparation is concerned, don't get too excited about deep tillage for a fall garden. Lightly work the soil enough to establish a seedbed; reserve your deep tillage for later in the fall. Also, don't concentrate on adding a lot of organic matter and fertilizer for the fall garden. The organic matter can be added later in the fall with the deeper tillage, and excessive fertilizer application in hot weather is not a good idea. If you have some crop residue to remove from a previous crop, chop the residue with a lawn mower and lightly till the soil surface after the residue has had a chance to dry for 2 to 3 days. (Ward Upham)

Pests:
Chiggers

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Chiggers are mites, not insects. And like all mites, the adults have eight legs. However, the larva only has six legs. Though the bright red female adult is tiny (about 1/20th of an inch) the larva is much smaller (about 1/150th of an inch). Only the larvae are parasitic and attack animals. The larva injects digestive juices into the skin, which causes a rapid swelling. In the center of the swelling is a "feeding tube" from which the chigger sucks out liquefied skin cells. Feeding usually continues for 2 to 4 days.
 
Protection from chiggers uses two approaches. The use of a repellent can discourage chiggers from attacking. The most effective repellents are Deet and permethrin. Both are applied to clothing. The second approach seeks to reduce chigger populations. Keeping the lawn mowed regularly can help, but large populations may require the use of an acaricide. Effective products include bifenthrin (Talstar, Hi-Yield Bug Blaster II, Hi-Yield Bug Blaster Bifenthrin, and Ortho Lawn Insect Killer Granules), cyfluthrin (Tempo 20, Bayer Vegetable & Garden Insect Spray) and carbaryl (Sevin). For more information, see the K- State Research and Extension publication titled, “Chiggers” at:  http://www.ksre.ksu.edu/bookstore/pubs/MF2107.PDF  (Ward Upham)

Miscellaneous:
Pokeweed

pokeweed
A number of people have asked the name of the weed with the large leaves and purple-black berries that hang in a cluster. This perennial is known as pokeweed. All parts of this plant are poisonous, especially the roots. Signs of poisoning include abdominal cramps, diarrhea, vomiting, weakness, drowsiness and difficulty in breathing. One of the toxins found in pokeweed is the protein lectin, which can cause abnormalities in white blood cells.
 
Surprisingly, young leafy springtime shoots are sometimes eaten after thorough cooking. Though cooking eliminates most of the toxins, there is still a danger of being poisoned from handling and preparing the shoots as well as ingesting improperly cooked plants.
 
Berries can be attractive to children. Cut down and discard pokeweed that might come into contact with kids. This plant is a perennial. You may want to spray it with a herbicide next year before it is large enough to be attractive to children. (Ward Upham)

Pesticide Effectiveness

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​We sometimes receive complaints from homeowners regarding the lack of effectiveness of various pesticides. There can be a number of reasons for this lack of efficacy. Here are some of the common ones:
 
1. Lack of good foliage penetration. This often is a problem when spraying for bagworms on junipers.  The spray must penetrate the foliage and reach the bagworms toward the inside of the plant. High-pressure commercial sprayers are able to get the spray to the insects but homeowner models are much more problematic. With pump-up sprayers, you may have to push the wand through the outer layer of foliage to reach insects toward the inside of the plant.
 
2. Not spraying where the insect is. Many of our insects and mites feed on the underside of leaves. If the plants are sprayed over the top, little to no pesticide reaches the pests. This problem is often seen with spider mites on broadleaf plants and cabbage worms on cabbage, broccoli and cauliflower.
 
3. Maturity of pest. Insects become much more difficult to control when they become adults. For example, Sevin does a good job of controlling young, early instar grasshoppers but is much less effective on adults.
 
4. Level of disease pressure. Most fungicides are better used as preventatives than as curatives. If a disease gets firmly established, it may be difficult to bring it back under control. For example, chlorothalonil is effective in controlling early blight and Septoria leaf spot on tomato if used as a preventative. However, chlorothalonil will not control these diseases on badly infested plants.
 
5. Choosing the wrong product. Homeowners often use a product they have on hand. However, products differ markedly in how well they control specific pests. Make sure the pest you wish to control is on the label. Unfortunately, even labeled products may vary in effectiveness. Check K-State Research and Extension recommendations for products.
 
6. Using the wrong rate. Using less than recommended rate can reduce effectiveness but using more can also cause problems.  For example, using a systemic herbicide such as Roundup at higher than recommended rates can burn off the top of the plant before the herbicide is translocated to the roots, thereby reducing effectiveness.
 
6. High pH spray water. Certain pesticides are not stable in high or low pH water. Following are  some examples.

* Captan has a half-life of 3 hours at a pH of 7.0, but only 10 minutes at a pH of 8.0.
* Carbaryl (Sevin) has a half-life of 24 days at pH 7.0, but only 1 day at pH 9.
 
The half-life of a product is the amount of time it takes for half of the product to be neutralized. For example, if you apply 3 ounces of a product to a gallon of water and the half-life is 8 hours, only half of the product is still active at 8 hours, one-fourth of the product is active 16 hours and 1/8 of the product is still active at 24 hours. (Ward Upham)
 
Contributors: Ward Upham, Extension Associate

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Horticulture Newsletter 2016, No. 28

7/12/2016

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Video of the Week:
Dividing Iris

Upcoming Events:

July 26        K-State Flower Field Day, Olathe
https://www.eventbrite.com/e/k-state-flower-field-day-tickets-26105824223
 
July 30        K-State Research & Extension Center Horticulture Field Day, Olathe
http://www.johnson.k-state.edu/lawn-garden/horticulture-field-day.html
 
August 4     Kansas Turfgrass Field Day, Manhattan
https://turffieldday.eventbrite.com

Vegetables:
Heat Stops Tomatoes from Setting Fruit

tomato flower
Temperatures that remain above 75 degrees F at night and day temperatures above 95 degrees F with dry, hot winds will cause poor fruit set on tomatoes. High temperatures interfere with pollen viability and/or cause excessive style growth leading to a lack of pollination.
 
It usually takes about 3 weeks for tomato flowers to develop into fruit large enough to notice that something is wrong and an additional week before tomatoes are full size and ready to start ripening.
 
Though there are "heat-set" tomatoes such as Florida 91, Sun Leaper and Sun Master that will set fruit at higher temperatures, that difference is normally only 2 to 3 degrees. Cooler temperatures will allow flowers to resume fruit set. (Ward Upham)

Spider Mites on Tomatoes

spider mite damage on tomatoes
We have seen some impressive spider mite damage on tomatoes. This is a little surprising considering how little hot and dry weather we have had this summer.
 
Look for stippling on the upper surface of the leaves as well as some fine webbing on the underside of the leaves. These tiny arthropods (they are not true insects) are often difficult to see due to their size and their habit of feeding on the underside of leaves. If mites are suspected, hold a sheet of white paper beneath a leaf and tap the leaf. Mites will be dislodged and can be seen as tiny specks on the paper that move about.
 
Spider mite control can be challenging. A strong jet of water can be used to remove the mites but may not be as easy as it sounds. A high-pressure directed spray is needed to dislodge the mites. Since spider mites feed on the underside of the leaves, the spray is most effective if it comes from below. This can be difficult to accomplish with a thumb over the end of the hose.
 
Some gardeners use a water wand hooked to a shut-off valve. The water breaker is then replaced by a brass nozzle.  Horticultural oils and insecticidal soaps (Safers, for example) can also be helpful. Spray early in the morning when temperatures are cooler and plants have rehydrated. Resprays will likely be needed. (Ward Upham)

Fruit:
When to Pick Peaches

peach ripening
Peaches are best when ripened on the tree but fruit growers may wish to pick a bit early to prevent damage from birds, have a higher pectin content for jams and jellies or to have firmer fruit for canning.
 
Peaches that are mature enough to pick are still hard. They do not give when lightly squeezed. However, these peaches will ripen off the tree and will have very good quality. They may not be quite as sweet as a tree-ripened peach but are still very good. So what do we look for to tell if a peach is mature enough to harvest? Let’s look at a couple of factors.
 
Color:  The reddish coloration is not a good indicator. Look instead for what is called the “ground color.” This is the part of the peach that does not turn red; for example, around the stem. The ground color of the peach will lose its greenish tinge and turn yellow when the peach is mature enough to harvest. I use this characteristic more to determine when NOT to pick a peach. If there is any green in the ground color, it is too early. If the ground color is yellow, then I move to the next characteristic.
 
Ease of Removal:  A mature peach will separate easily from the branch if the peach is lifted and twisted. If it doesn’t, it is not mature enough to pick yet.  All peaches will not be ready to pick at the same time. Pick only those that are ready and come back later for more. It often takes 3 to 5 pickings to harvest a peach tree.
 
Peaches that are picked early but will be used for fresh eating should be allowed to ripen inside at room temperature. Once they are ripe, they can be refrigerated to preserve them for enjoyment over a longer period of time. (Ward Upham)

Pests:
Green June Beetles: Out-and-About

Green June beetles
Green June beetle (Cotinis nitida) adults are actively flying around and “bumping” into people and objects. Adults are 3/4 to 1.0 inches in length, and velvety-green, tinged with yellow-brown coloration. Green stripes with yellow-orange margins extend lengthwise on the front wings. The underside of the body is distinctly shiny and metallic green or gold. Adults fly like “dive bombers” over turfgrass for several weeks in mid-summer.
 
The green June beetle has a one-year life cycle, and overwinters as a mature larva (grub). Adults emerge in late-June and are active during the day, resting at night on plants or in thatch. The adults produce a sound that resembles that of bumble bees. Adults will feed on ripening fruits and may occasionally feed on plant leaves. The male beetles swarm in the morning, “dive bombing” to-and-fro above the turfgrass searching for females that are located in the turfgrass (they are desperately seeking a mate). Females emit a pheromone that attracts males. Eventually, clusters of beetles will be present on the surface of the soil or turfgrass with several males attempting to mate with a single female (I think this qualifies as an “insect orgy”). Mated females that have survived the experience lay a cluster of 10 to 30 eggs into moist soil that contains an abundance of organic matter. Eggs hatch in about 2 weeks in early August and the young larvae feed near the soil surface. The larvae feed primarily on organic matter including thatch and grass-clippings; preferring soils that are excessively moist. Larvae are 3/8 (early instars) to 1.5 (later instars) inches in length, and exhibit a strange behavioral trait—they crawl on their back.  (Raymond Cloyd)

Flowers:
Dividing Iris

Iris rhizome
Bearded irises are well adapted to Kansas and multiply quickly. After several years, the centers of the clumps tend to lose vigor, and flowering occurs toward the outside. Dividing iris every three to five years will help rejuvenate them and increase flowering.
 
Iris may be divided from late July through August, but late July through early August is ideal.  Because iris clumps are fairly shallow, it is easy to dig up the entire clump. The root system of the plant consists of thick rhizomes and smaller feeder roots. Use a sharp knife to cut the rhizomes apart so each division consists of a fan of leaves and a section of rhizome. The best divisions are made from a double fan that consists of two small rhizomes attached to a larger one, which forms a Y-shaped division. Each of these small rhizomes has a fan of leaves. The rhizomes that do not split produce single fans. The double fans are preferred because they produce more flowers the first year after planting. Single fans take a year to build up strength.
 
Rhizomes that show signs of damage due to iris borers or soft rot may be discarded, but you may want to physically remove borers from rhizomes and replant if the damage is not severe. It is possible to treat mild cases of soft rot by scraping out the affected tissue, allowing it to dry in the sun and dipping it in a 10 percent solution of household bleach. Make the bleach solution by mixing one-part bleach with nine parts water. Rinse the treated rhizomes with water and allow them to dry before replanting.
 
Cut the leaves back by two-thirds before replanting. Prepare the soil by removing weeds and fertilizing. Fertilize according to soil test recommendations or by applying a complete fertilizer, such as a 10-10-10, at the rate of 1 pound per 100 square feet. Mix the fertilizer into the soil to a depth of 6 inches. Be wary of using a complete fertilizer in areas that have been fertilized heavily in the past. A growing number of soil tests show phosphorus levels that are quite high. In such cases, use a fertilizer that has a much higher first number (nitrogen) than second (phosphorus). (Ward Upham)

Ornamentals:
What's in a Name?

Bear's Breeches
I recently received a kind email from an Extension Master Gardener noting an unfortunate typo on the “Evergreen Shrubs for Kansas” (MF3117) publication. On page 5, I mistakenly swapped one letter in the common plant name rendering Taxus xmedia’s title “Anglojap Jew” instead of “Anglojap Yew.” This is, indeed, distasteful and I appreciate the thorough review, which noted the appropriate name use on pages 3 and 6 of the same publication.
 
This is a teachable moment, however, and I wanted to take the opportunity to clarify that the common name “Anglojap” does not reference a racial slur of any kind. As with many plants, it references its geographic place of origin. “Anglo” comes from “anglicus” meaning “From England; English.” Taxus is native to Japan, Korea and Manchuria, thus the second part of the common name references “japonicus” or Japan. Taxus xmedia is a hybrid of Taxus baccata (English Yew) and Taxus cuspidata (Japanese Yew) and has been in production with the common name Anglojap Yew since 1900.
 
Resources to help understand plant names include, of course, Michael Dirr’s “Manual of Woody Landscape Plants.” Another interesting book is A.W. Smith’s “A Gardener’s Handbook of Plant Names: Their Meanings and Origins.” Fun tidbits from the “A” section of this compendium include:

acanth [ak-anth]
In compound words signifying spiny, spiky, or thorny.
 
Acanthus [ak-AN-thus]
Greek name meaning thorn. In America it is called “bear’s breech” from the size and appearance of the leaf which is very big, broad, and distinctly hairy. The acanthus leaf was a favorite decoration in classical sculpture, as in the capital of the Corinthian column. In England the bear has been dressed up and it is now called “bear’s breeches” despite long-standing authority to the contrary.
 
Bear’s Breeches (Acanthus mollis) is an herbaceous perennial hardy in zones 6 to 10 and is marginal in Kansas. The species name “mollis” means “Soft; with soft hairs.” So the entire Latin name describes the plant leaves: they are large, broad, and covered with soft hairs. This is to say nothing of the flower on bear’s breeches, which is a quite lovely, bold spike of maroon and white that look somewhat like snapdragon flowers and can rise two to three feet above the foliage. Other species of Acanthus include Acanthus spinosus (spiny leaves), Acanthus hungaricus (from the country of Hungary, native to the Balkans, Romania, Greece) and Acanthus montanus (pertaining to mountains, native to Western tropical Africa). Some of these names remind me of the spells in the Harry Potter universe—not so different from the English names with which we’re familiar.
 
Back to the “A” section and I’m learning lots of plant history. Take Abelia for instance:
Abelia [ab-EE-lia]
Ornamental shrubs named for Dr. Clark Abel (1780-1926), who, at the suggestion of Sir Joseph Banks, accompanied Lord Amherst on his embassy to Peking (1816-1817) as botanist. Much of his collection was lost by shipwreck on the way home to Kew. Except for Russian ecclesiastical mission, no European naturalist was to visit China for nearly thirty years thereafter, Robert Fortune (see Fortunella) being among the first to follow. Abel died in India while serving as personal physician to Lord Amherst, who was by that time Governor-General.
 
I love history! I am always interested in learning about the lives of people who were passionate about similar things. The entry on Fortunella was quite interesting…and long. Robert Fortune (Scottish horticulturalist and plant collector) was a rather well-traveled man in the 1800s (China, India, United States). Most other entries in A.W. Smith’s book are descriptive of origin (“chinensis” = “Chinese”) or botanic characteristic (“serratus” = “saw-toothed” or “hippocastanum” = “Latin name for the horse-chestnut. There is a clearly marked horseshoe under the leaf axils.”).  A few are just really informative related to the historical importance of the plant or people involved in discovering and naming them. As a side note, I have colleagues who regularly go on plant collecting trips so I’m aware that plant names are still being determined in present times. I’m sure taxonomists will continue to delve deep into the appropriate nomenclature as time goes on. Even in my own relatively short time as a horticulturalist I know several plants for which the scientific name has been changed (and in some cases, changed back!).
 
Suffice it to say, there is much more to know about scientific plant names, their meanings and origins. However, I hope this narrative provides some perspective on the primary common name of such a common landscape plant in our region as Anglojap Yew. Naming a plant is an honor and never meant to cause harm or disrespect. Often their names even include warnings as in firethorn, Pyracantha coccinea, which means “thorns with scarlet fruit.” Just make sure to steer clear of Toxicodendron radicans (a toxic plant with rooting stems—poison ivy) or Ilex vomitoria (yaupon holly—great landscape shrub actually, just, you know, don’t eat large quantities of it, okay?) this summer.
 
The aforementioned publication has been updated in the electronic file on the KSRE Bookstore, for those of you wishing to have a new copy. We’re grateful for folks who take the time to let us know when something like that needs to be repaired. (Cheryl Boyer)
 
Contributors: Raymond Cloyd, Extension Entomologist; Cheryl Boyer, Nursery Crops Specialist; Ward Upham, Extension Associate

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Horticulture Newsletter 2016, No. 18

5/3/2016

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Video of the Week:
Hydrangea Macrophylla

Turfgrass:
Fertilize Irrigated Cool-Season Lawns in May

tall fescue lawn
May is an excellent time to fertilize cool-season lawns such as tall fescue and Kentucky bluegrass if they will be irrigated throughout the summer. Non-irrigated lawns often go through a period of summer dormancy because of drought and do not need this fertilization.
 
May is a good time to fertilize because the springtime flush of growth characteristic of these grasses has tapered off, so the fertilizer you apply will be less likely to cause excessive shoot growth than if you fertilized at a full rate in April. Slow-release nitrogen sources are ideal. These nitrogen sources promote controlled growth, which is desirable as the stressful summer weather approaches. Relatively few fertilizers available to the homeowner supply ALL of the nitrogen in the slowly available form. But one such product that is widely available is Milorganite. Other such products available in the retail market include cottonseed meal, alfalfa-based fertilizers, and any other products derived from plants or animals. (Bloodmeal is an exception, and contrary to popular belief, the nitrogen it supplies is quickly available.) These products are all examples of natural organic fertilizers. They typically contain less than 10 percent nitrogen by weight, so compared to most synthetic fertilizers, more product must be applied to get the same amount of nitrogen. Translation: they are more expensive! Apply enough to give the lawn one pound of nitrogen per 1,000 square feet. For example, if the fertilizer is 6 percent nitrogen by weight, you will need to apply almost 17 pounds of fertilizer product per 1,000 square feet. Summer lawn fertilizers that contain at least a portion of the nitrogen as slow-release are fine to use as well. Be sure to follow label directions. If cost is prohibitive, you can use the less expensive quick-release (i.e., soluble) sources, but split the application into two doses as follows: apply enough to give the lawn 0.5 lb nitrogen per 1,000 square feet in May and again in early June. (Ward Upham)

Fruit:
Be on the Lookout for Peach Leaf Curl and Plum Pocket

peach leaf curl
Peach leaf curl is a fungus disease that causes developing peach leaves to become puckered and distorted and show a reddish-green hue. A similar disease called plum pocket may develop on American and sand hill plums. Plum pocket results in formation of distorted, light green, bladder-shaped fruit. Asian and European plums are not susceptible to the local strain of plum pocket. Unfortunately, it is too late to control these diseases with fungicides this year.
 
Trees that are severely infected with peach leaf curl are likely to lose many leaves. If trees are healthy, new leaves will grow. Indicators of a healthy tree are large, deep green leaves and last year's growth being at least 18 to 24 inches long. If these tree vigor indicators are not present, especially if there was only 12 inches or less of growth last year, then a fertilizer application would be helpful.
 
The fertilizer should be spread on the soil under the branch area. Apply 1 and 1/3 to 2 cups of a 13-13-13 fertilizer under the branch area. If a soil test indicates that only nitrogen is needed, use 1/3 to 1½ cups of nitrate of soda (16-0-0) instead of the 13-13-13. You may also substitute a high nitrogen fertilizer such as a 27-3-4, 30-5-4 or something similar for the 13-13-13, but use only half the amount used for nitrate of soda. The sooner fertilizer is applied, the more immediate benefit it will have in promoting new leaf growth. Both peach leaf curl and plum pocket can be controlled with a single fungicide application applied this fall after leaf drop or early next spring before bud swell.
 
Effective fungicides include Bordeaux mixture and chlorothalonil (Bravo, Daconil and others). Be sure to cover the entire tree including the bark and trunk. (Ward Upham)

Fruit Sprays and Spray Water pH

commercial sprayer
Two of the common pesticides used in fruit tree sprays are malathion (for insects) and captan (for diseases). Unfortunately, both of these products are subject to alkaline hydrolysis. This is a process whereby certain pesticides will break down when mixed with high pH water. So let’s say you mix up your spray mixture by adding malathion and captan to 5 gallons of water. If that water has a pH of 7, the captan will break down so that only half of it will still be present in 8 hours.
 
However, if the water you use has a pH of 10, half the captan will break down in 2 minutes. Malathion isn’t nearly as sensitive but still will break down under high pH conditions though it is stable at a pH between 5 and 7. Note that alkaline hydrolysis does not affect all pesticides. Captan is the exception, not the rule. 
 
So, how do you bring down the pH of your spray water if it is high? Commercial people use buffering agents but that may be difficult for homeowners to find. Food grade citric acid can help. If you have a pH of 8.0, add 2 ounces of this citric acid per 100 gallons of water (1 and 1/4 teaspoons per 10 gallons) to bring the pH down to about 5.5. (Ward Upham)

Peaches and Apricots

fruit tree
Some parts of Kansas will have at least a partial peach crop that wasn’t killed by late frosts. To take advantage of this good fortune certain things should be done as the fruit matures to ensure a good harvest.
 
Control insects and diseases: Though it is too late to control peach leaf curl (see http://www.hfrr.ksu.edu/doc3168.ashx ), it is possible to control scab and brown rot.  Insects of concern are plum curculio, oriental fruit moth, plant bugs, and stink bugs. Use Captan or Immunox to control the diseases, and malathion to control the insects. Spray every 10 to 14 days. Pay attention to the waiting period between the last spray and harvest. See the publication, “Fruit Pest Control for Home Gardens” at http://www.ksre.ksu.edu/bookstore/pubs/c592.pdf   for details including organic controls.
 
Thin peaches: Thin peaches to 1 every 6 to 8 inches to maximize fruit size and to decrease the load on the branches. As a general rule, we need about 40 leaves per peach for maximum quality. Peaches are borne in clusters, so calculate how many a branch can support by dividing the length of the branch in inches by 7. As long as there is an average of 7 inches of branch length per peach, it doesn’t matter whether the peaches are in clusters or not.
 
Water Trees as Needed:   The most critical time for adequate water is during the pit hardening stage which usually lasts between 2 to 4 weeks. Cut open a few peaches to determine when the pit starts to harden or become woody. Irregular watering during this period can lead to split peaches.
 
Prop up branches if needed: Prop up branches if the fruit load is so heavy the tree may break apart. Use boards with a “V” cut in one end to support the branch. Prune the branch back to a smaller side branch next spring (March). (Ward Upham)

Flowers:
Blackspot of Roses

blackspot of roses
A common disease of roses is blackspot, a fungus disease that can cause defoliation of susceptible plants. Look for dark, circular lesions with feathery edges on the top surface of the leaves and raised purple spots on young canes. Infected leaves will often yellow between spots and eventually drop.

 The infection usually starts on the lower leaves and works its way up the plant.  Blackspot is most severe under conditions of high relative humidity (>85%), warm temperatures (75 to 85 degrees F) and six or more hours of leaf wetness. Newly expanding leaves are most vulnerable to infection. The fungus can survive on fallen leaves or canes and is disseminated primarily by splashing water.
 
Cultural practices are the first line of defense.
 
1. Don't plant susceptible roses unless you are willing to use fungicide sprays. For a list of blackspot resistant varieties, go to:  http://www.ppdl.purdue.edu/ppdl/weeklypics/3-22-04.html
 
2. Keep irrigation water off the foliage. Drip irrigation works well with roses.
 
3. Plant roses in sun in areas with good air movement to limit the amount of time the foliage is wet.
 
4. Remove diseased leaves that have fallen and prune out infected rose canes to minimize inoculum.
 
If needed, protect foliage with a regular spray program (10- to 14-day schedule) of effective fungicides. Recommended fungicides include tebuconazole (Bayer Disease Control for Roses, Flowers and Shrubs), myclobutanil (Immunox, Immunox Plus), triticonazole (Ortho Rose & Flower Disease Control) and chlorothalonil (Broad Spectrum Fungicide, Garden Disease Control, others). (Ward Upham)

Miscellaneous:
Excessive Rain Can Cause Leaf Problems

reddening leaves
Leaves Turning Yellow or Red: In Kansas we often see chlorosis (yellowing) of plant leaves due to high pH soils making iron unavailable.  However, there can other causes that result in similar symptoms. For example, we have received so much rain in certain parts of the state recently that plants are unable to take up the nutrients needed to maintain a good green color. The cause of this condition is actually a lack of oxygen in the soil due to soil pore space being filled with water.
 
This lack of oxygen to the roots often results in a yellowing of foliage. In certain plants such as oaks and maples, however, it may also lead to a reddening of some of the newer leaves. Fortunately, color changes due to wet soils will be corrected as soils dry. Plants should regain their color when we return to more normal weather.
 
Trees Shedding Leaves: If trees shed leaves in a general shedding with all parts of the tree losing some leaves, then there is no cause for concern. A general shedding of the leaves is most often due to weather turning hot and dry. The tree drops leaves because the root system can no longer keep up. Dropping leaves helps balance the amount of water available from the root system and the amount needed by the leaves.
 
However, the same thing can happen if the soil is too wet. A lack of oxygen in the soil compromises the root system so it can no longer support all the leaves. Therefore, the tree drops some leaves to bring the tree roots and leaves back into balance. The tree will retain more than enough leaves to remain healthy. (Ward Upham)

Recent Rains Trigger Mushroom Development

mushrooms in lawn
The frequent, heavy rains in certain areas of the state have resulted in the appearance of mushrooms in home lawns and landscape beds.  Although mushrooms are often spectacular in size and color, most are relatively harmless to plant life. Some of these mushrooms are associated with arc-like or circular patterns in turfgrass called fairy rings. The ring pattern is caused by the outward growth of fungal mycelium. The mycelium forms a dense, mat-like structure in the soil that decomposes organic matter. This decomposition releases nitrate into the soil, which in turn stimulates the growth of the grass at the outer portion of the ring. This results in a dark green appearance of the grass at the margin of the ring.
 
Unfortunately, the thick fungal mat formed by the fungus interferes with water infiltration. The fungus also may release certain byproducts that are toxic to the turf. This can lead to dieback of the turf close to the ring. Fairy rings are difficult to control. You can sometimes eliminate the ring by digging to a depth of 6 to 12 inches and 12 inches wide on both sides of the ring, refilling the hole with non-infested soil. Or you can try to mask the symptoms by fertilizing the rest of the lawn so that it is as dark green as the ring. This often isn't a good idea because it tends to promote other turf problems. Commercial people can use certain fungicides to control fairy rings but these products are not available to homeowners. See http://www.ksre.ksu.edu/bookstore/pubs/EP155.pdf  for more info on these fungicides.
 
Some mushrooms in lawns are not associated with fairy rings. These may be mycorrhizal (symbiotic association with tree roots) or saprophytic (live on dead organic matter such as wood, etc.) in the soil. Because some of these mushrooms are beneficial, you don't really want to kill them. Besides, a fungicide spray to the mushroom itself does little good. Remember the mushroom is simply the fruiting structure of the organism. Most of the fungus is below ground and inaccessible to the chemical. If mushrooms are a nuisance, pick them and dispose of them as soon as they appear. Remove sources of large organic debris from the soil. Also, mushrooms tend to go away as soil dries. Patience may be the best control. Some of the mushrooms in the lawn are edible, but others are poisonous. Never eat mushrooms unless you are sure of their identity. (Ward Upham)

Pests:
Aphids

aphids
Aphids are small insects, about an eighth of an inch long. They are soft-bodied, pear-shaped and of many colors, such as green, black, gray, yellow or red. Some are winged during certain times of the year.
 
Aphids feed by sucking sap from buds, leaves, twigs and developing fruit. Most of that sap is passed through their body and ejected through two small “pipes” known as cornicles that project from the rear of their bodies. This ejected, sticky
material is called honeydew. This honeydew often becomes black with sooty mold fungus. Automobiles parked under trees with large aphid populations will often be spotted with honeydew. Though the finish will not be harmed by the honeydew, it is a hassle to clean off.
 
Aphids usually are controlled effectively by nature. Adverse weather conditions such as beating rains and low temperatures, as well as fungus diseases, insect predators and parasites, keep the aphids in check. Aphid enemies include lady beetles, syrphid fly larvae, aphis lions and small wasp parasites known as braconids.
 
Most insecticide applications destroy beneficial insects as well as pests and leave trees or shrubs unprotected if pest resurgence occurs. Because beneficial insects play an important role in natural aphid control, try washing aphids away with a forceful stream of water (if practical) before using insecticide sprays.
 
If control measures are warranted, use insecticidal soaps, horticultural oils, malathion, cyfluthrin or permethrin. Reapplication may be needed. Imidacloprid (Annual Tree and Shrub Insect Control, 12 Month Tree & Shrub Insect Control, Max Tree and Shrub Insect Control, Bonide Systemic Granules IC, Bayer Tree and Shrub Insect Control) is a systemic insecticide that can be used to prevent aphid populations from building but must by applied early to allow time for the pesticide to move to the new growth. This time period may vary from one week to three months depending on the size of the plant with very large trees taking the most time. (Ward Upham)

Sawfly Larvae on Ash

sawfly larvae
We had a report last week from the Wichita area that a number of ash trees have ash sawfly larvae feeding on the leaves.
 
These sawfly larvae are a light green color with a broad, whitish stripe on the top side.  In the middle of the whitish stripe there appears to be a darker green stripe that is actually the digestive tract of the insect.  Though sawfly larvae resemble caterpillars, they have at least six pairs of "stublike" prolegs behind the three pairs of true legs on their abdomen. (Caterpillars never have more than five pairs of prolegs.)
 
There are usually no detrimental effects to the health of the tree if nature is allowed to run its course. Even if all the leaves are eaten, it is early enough in the growing season for trees to put out a complete new set of leaves and still has enough time to make all the food reserves needed to survive the coming winter. However, if control is desired, a number of insecticides can be used for control including cyfluthrin (Bayer Lawn and Garden Multi-Insect Killer), malathion, esfenvalerate (Monterey Bug Buster II) and carbaryl (Sevin). An effective organic product is spinosad (Captain Jack’s Deadbug Brew; Fertilome Borer, Bagworm, Leafminer and Tent Caterpillar Spray; Monterey Garden Insect Spray). Horticultural oils and insecticidal soaps are also effective because of the soft skin of sawfly larvae. (Ward Upham)
 
Contributors:  Ward Upham, Extension Associate

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Horticulture Newsletter 2016, No. 11

3/15/2016

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Video of the Week:
Pruning Fruit Trees​

Fruit:
Frost Tolerance of Apricots and Peaches

Peach flowers
Growers of apricots and peaches often wonder at what temperature fruit buds are killed especially in years where we have an early spring.  These two tree fruits bloom very early and are often caught by a late frost. The following will give you some guidelines but remember that the actual damage is going to be influenced by the weather before the temperature drops. An extended warm spell before the cold snap may result in more damage due to a loss in cold hardiness. The stages listed are for the fruit buds.
 
Apricot
 
Stage               10% Kill (°F)         90% Kill (°F)
First white             24                              14
First Bloom          25                               19
Full Bloom            27                              22
In the Shuck         27                               24
Green Fruit          28                               25

Peach

Stage              10% Kill (°F)          90% Kill (°F)
Swollen bud          18                                2
Half-inch green   23                                5
Pink                         25                               18
Bloom                     27                               24
Petal fall                28                               25
Fruit set                 28                               25

To check for low temperature injury to fruit buds or blossoms, use a sharp knife and cut them in half longitudinally (from top to bottom). If the tiny seed in the center is white to cream color no damage has been done. But if the seed in several buds or blossoms is dark brown or black, it has been killed.It is possible to give some protection to blossoms from freezing by covering the tree with a bed spread, blanket or similar fabric. Old-fashioned Christmas lights  distributed around the tree will help to give additional protection. The newer, smaller Christmas lights do not give off enough heat and are not recommended. Of course the practicality of this method of protection depends upon the size and number of trees.
 
Sprinkling the tree with water throughout the freezing period can also protect the blossoms. Sprinklers should be started before the temperature drops to freezing to be sure ice does not block the garden hose or water line. Continue until the temperature warms. With this protection method, there is the potential of creating an ice storm. If temperatures remain below freezing for several hours, ice will accumulate on the branches and limbs. The weight from the ice may cause branches and limbs to break causing severe, and possibly permanent, damage to the tree structure. Also, if water drainage from the soil is slow and the water displaces oxygen from the roots, damage to trees may result. (Ward Upham)

Vegetables:
Controlling Weeds in Home Garden Asparagus Beds

asparagus emerging
The best time to control weeds in asparagus is early spring before the asparagus emerges. A light tilling (or hoeing) that is shallow enough to avoid the crowns will eliminate existing weeds. Many gardeners like to mix in organic matter during the same operation.
 
Herbicides can be used before asparagus emerges. Glyphosate (Roundup, Killzall) will kill weeds that are actively growing, and the preemergence herbicide trifluralin can be used to kill weed seeds as they germinate. Trifluralin is found in several products, but not all of them list asparagus on the label. Those that do have asparagus on the label include Miracle-Gro Weed Preventer Granules and Monterey Vegetable and Ornamental Weeder. Mulch can also be used to keep weeds from invading.
 
No herbicides can be used during harvest. The end of harvest presents another opportunity. Remove all fern and spears and apply Roundup to control virtually all of the weeds present.  Past the harvest season and after regrowth of the asparagus, options are limited. Products that contain sethoxydim can be applied to asparagus to kill grassy weeds. Sethoxydim has no effect on broadleaves including asparagus. Two sethoxydim products available to homeowners and
labeled for asparagus are Monterey Grass Getter and Hi-Yield Grass Killer. With broadleaves, the only option is to pull them and look forward to next year. (Ward Upham)

Remove Fern and Fertilize Aspargus

old asparagus ferns
If you haven’t removed last year’s growth from asparagus plants, now is the time. Asparagus comes up around the first of April in Manhattan but will be earlier in southern Kansas and a bit later further north.

Also, asparagus benefits from a fertilizer application early spring. Fertilize according to a soil test or add 1 to 2  pounds of a 10-20-10 fertilizer per 20 feet of row before growth starts. If a soil test shows that only nitrogen is needed, apply 1 pound of a 16-0-0 product or ½ pound of a 30-4-5, 27-3-3 or similar fertilizer per 20 feet of row. Incorporate lightly with a tiller or rake in fertilizer before spears emerge. Fertilize again at the same rate after the last harvest. (Ward Upham)

Flowers:
Preventing Weeds in Flower Beds

flower bed
Often mulch does a good enough job in perennial flower beds to prevent weeds but sometimes the mulch needs a little help. In annual beds, judicious hoeing will keep weeds down until the foliage forms a canopy that prevents weed germination.  However, a lack of time may have you considering an easier way than hoeing or pulling weeds that come through mulch. Preemergence herbicides can help though you should not expect 100% control.
 
Preemergence herbicides do not keep the weed seed from germinating but kill the young plant as it starts to grow. It is necessary to water these products in (1/4 inch of water) so that the young weed root will contact the herbicide. Be aware that most of these products are more effective on grassy weeds such as crabgrass rather than broadleaves such as dandelions or spurge.
 
These herbicides often have no effect on existing plants, so they must be applied before the weed seed germinates. Additionally, preventers do not last forever once applied to the soil. Microorganisms and natural processes begin to gradually break them down soon after they are applied. However, all should last long enough so that you get canopy cover before the herbicide wears off.
 
Read the label for information on when to apply the product. Also, be sure the ornamental plants within the bed area are on the label before purchasing the product. See below for products we can use.
 
Dimension (dithopyr)
- Hi-Yield Turf & Ornamental Weed and Grass Stopper
- Bonide Crabgrass & Weed Preventer

​Treflan (trifluralin)
- Hi-Yield Herbicide Granules Weed and Grass Preventer
- Miracle Gro Garden Weed Preventer
- Preen Weed Preventer
(Ward Upham)

Turfgrass:
Managing Turf in the Shade

shaded turf
Turfgrasses differ in their capacity to grow in shade. Among Kansas turfgrasses, tall fescue is the best adapted to shade though it isn’t all that good. Although the fine fescues (i.e., creeping red, chewings, hard and sheep) have better shade tolerance, they lack heat tolerance and typically decline during hot Kansas summers. The warm-season grasses have the poorest shade tolerance, although zoysia does better than Bermuda or buffalo. Where shade is too heavy for fescue, there are other courses of action. The most obvious is to either remove trees, or to prune limbs and thin the tree canopies. Grass will do better under openly spaced trees than under closely spaced trees. Pruned limbs and thinned canopies will allow more sunlight to directly reach the turfgrass. If possible, raise the mowing height in the shade to compensate for the more upright growth of the leaves, and to provide more leaf area for photosynthesis. The thin, weak turf in the shade may tempt you to fertilize more.
 
Remember the problem is lack of light, not lack of fertility. Too much nitrogen in the spring causes the plant to grow faster and may result in weak plants. The nitrogen rate for shaded grass should be cut back to at least half of that for grass in full sun. Late fall fertilization after tree leaves have fallen, on the other hand, is important for shaded cool-season turfgrasses and should be applied at a full rate. Irrigate infrequently but deeply. Light, frequent irrigation may encourage tree feeder-roots to stay near the surface, which increases competition between the trees and the turf. Restrict traffic in the shade.
 
Many times, the best choice for shaded areas is switch from a turfgrass to a more shade-tolerant plant. For example, English ivy and periwinkle (Vinca minor) are much more shade tolerant than any turfgrass adapted to our area. Another option is simply to mulch the area where turf doesn’t grow well. The trees will love the cool, moist soil and the absence of competition. (Ward Upham)

Ornamentals:
Brown Coloration on Junipers

Juniper male
Certain eastern redcedar and various other junipers are showing a brownish cast when viewed from a distance. This may be the male flowers. Male flowers are on the tips of the leaves and look somewhat like a cross between a miniature hand grenade and a pinecone. Shaking the branches on dry days will often result in a cloud of pollen being released.
 
Most junipers are dioecious, meaning they have both male and female plants. About half the junipers (the males) will have this coloration. The female flowers are much less obvious. If you have clients who are concerned about this brown coloration, have them check the plants to ensure the male flowers are the cause. If they are, assure them that this is normal and will fade with time. (Ward Upham)

Miscellaneous:
Adding Organic Matter in the Spring

adding organic matter
Organic matter is a good way to improve garden soil as it improves a heavy soil by bettering tilth, aeration and how quickly the soil absorbs water. However, organic matter added in the spring should be well decomposed and finely shredded/ground. Manures and compost should have a good earthy smell without a hint of ammonia. Add a 2-inch layer of organic matter to the surface of the soil and work the materials into the soil thoroughly. Be sure soils are dry enough to work before tilling as wet soils will produce clods.
 
To determine if a soil is too wet to work, grab a handful and squeeze. If water comes out, it is much too wet. Even if no water drips out, it still may not be dry enough to work. Push a finger into the soil you squeezed. If it crumbles, it is dry enough, but if your finger just leaves an indentation, more time is needed. Be sure to take your handfuls of soil from the depth you plan to work the soil because deeper soils may contain more moisture than the surface. (Ward Upham)
 
Contributors:  Ward Upham, Extension Associate

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Horticulture Newsletter 2016, No. 5

2/2/2016

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Video of the Week:
Tips for Growing Blueberries

Upcoming Events:

RetailWorks
February 4, 2016

Manhattan, KS

Grow Your Garden Center Business in 2016!
We hope you'll join us for this companion conference to the biennial NurseryWorks conference--RetailWorks on Thursday, February 4, 2016 in Manhattan. While NurseryWorks focuses on providing resources for wholesale nursery crop growers, RetailWorks is designed with the independent garden center's needs in mind. We continue to bring in 
outstanding national and local speakers on a variety of topics. You'll find great content and networking at RetailWorks 2016--get it on your calendar and register today!  For more information, go to: 
http://retailworks.weebly.com/ or register online at 
https://2016retailworks.eventbrite.com

Fruit:
Approaching Time for Peach Leaf Curl Control

peach leaf curl
If you have ever seen emerging peach leaves that are puckered, swollen, distorted and reddish-green color, you have seen peach leaf curl. Uncontrolled, this disease can severely weaken trees due to untimely leaf drop when leaves unfurl in the spring. Fortunately, peach leaf curl is not that difficult to control if the spray is applied early enough. However, by the time you see symptoms, it is much too late. As a matter of fact, fungicides are ineffective if applied after buds begin to swell. Don't spray when temperatures are below 40 degrees or will fall below freezing before the spray dries. Usually we can wait until March to spray but an extended warm period in February that encourages early bud swell may require spraying in late February. Though peach leaf curl can be controlled by a single fungicide application either in the fall after leaf drop, it is more commonly controlled in the spring.
    
There are several fungicides labeled for this disease including 
chlorothalonil (Ortho Garden Disease Control, Fertilome Broad Spectrum Fungicide, GardenTech Fungicide Disease Control and Daconil). Thoroughly cover the entire tree during application. Note that it is much easier to achieve good spray coverage if the tree is pruned before spraying. (Ward Upham)

Pruning Fruit Trees

fruit tree after pruning
Fruit trees can be pruned from now through March as long as the wood isn’t frozen. Following are some general recommendations on pruning mature fruit trees followed by more specific instructions on each species. If you have young fruit trees, see the accompanying article in this newsletter.

General Recommendations 
- Take out broken, damaged or diseased branches
- If two branches form a narrow angle, prune one out. Narrow angles are weak angles and tend to break during wind or ice storms.
- Take out all suckers. Suckers are branches that grow straight up. They may originate from the trunk or from major branches
- If two branches cross and rub against one another, one should be taken out.
- Cut back or remove branches that are so low they interfere with harvest or pruning. If cutting back a branch, always cut back to another branch or a bud. Do not leave a stub.
- Cut back branches to reduce the total size of the tree, if necessary.
- Thin branches on the interior of the tree.
Follow the steps above in order but stop if you reach 30% of the tree. For a short video on pruning, click here.

Specific Instructions
Peach and Nectarine: Peach and nectarine require more pruning than any other fruit trees because they bear fruit on growth from the previous year. Not pruning results in fruit being borne further and further from the center of the tree allowing a heavy fruit crop to break major branches due to the weight of the fruit. Prune long branches back to a shorter side branch

Apple: Apples tend to become overgrown if not pruned regularly. Wind storms and ice storms are then more likely to cause damage. Also, trees that are not pruned often become biennial bearers. In other words, they bear a huge crop one year and none the next. Biennial bearing is caused by too many fruit on the tree. Though pruning helps, fruit often needs to be thinned as well. The goal is an apple about every 4 inches. Spacing can vary as long as the average is about every 4 inches.

Cherry, Pear, Plum: Light pruning is usually all that is needed. Simply remove branches that are causing or will cause a problem according to the general recommendations above. (Ward Upham)

Pruning Young Fruit Trees

young fruit tree
 Young fruit trees should be pruned to begin developing a strong structure of the main or scaffold limbs. This will help prevent limb breakage over the years when the scaffolds carry a heavy fruit load. Apple, apricot, cherry, plum and pear trees generally are trained using the central leader system. The growth pattern for these trees is for a center branch to be dominant and to grow straight up. Peach and nectarine trees are normally pruned using the open center method because they do not have a strong tendency for one shoot or branch to dominate the growth of other shoots or branches. In this system, the tree is pruned to a vase-like pattern with no central leader.
    
Regardless of the system used, the three to four scaffold branches 
should:
     • Be no lower than 18 inches from the ground. This makes it easier to prune and harvest the tree once it matures.
     • Form wide angles (about 60 to 80 degrees) with the trunk. Wide angles are much stronger than narrow angles and are less likely to break under wind or ice loads.
     • Be distributed on different sides of the tree for good balance.
     • Be spaced about 6 to 10 inches apart on the trunk with no branch directly opposite or below another. (Ward Upham)

Pruning Overgrown Apple Trees

overgrown apple tree
Apple trees that are not pruned for several years will often produce so many branches that little energy is left for fruit 
production. Overgrown apple trees are also difficult to harvest and spray. Gardeners who have such a tree are often at a loss as to how to get it back in shape.
    
Often the best recommendation for such a tree is to make one 
pruning cut at ground level and start over with a new tree. However, trees may have sentimental value that will make revitalization worth the time and effort. Realize that this will be a multi-year process because no more than 30 percent of the tree should be removed in one year. Here 
are some steps to follow:

1. Remove all dead wood. This does not count toward the 30 percent.

2. Remove suckers from the base of the tree.

 3. Choose approximately six of the best branches to keep as scaffold branches. Remove all others. Branches should be cut flush to the branch collar. The collar is the natural swelling that occurs where a branch connects to the trunk or to a larger branch. Removing the collar would leave a larger wound that would take additional time to heal. Do not paint wounds. Wounds heal more quickly if left open. Candidates for removal include branches with narrow crotch angles, which are more likely to break in wind and ice storms, and those that cross branches you will save. This may be all that is possible the first year if the 30 percent threshold has been reached.
    
4. Thin the branches on each scaffold branch. Remove crowded 
branches to open up the tree to light and allow humidity to escape. Shorten each scaffold branch by cutting back to a side branch. When you are through, the tree should have enough wood removed so that a softball can be thrown through the tree.
    
Severe pruning often will cause an apple tree to produce vigorous 
side shoots from the trunk called water sprouts. Main branches will also produce suckers that grow straight up. The suckers and water sprouts should be removed throughout the growing season so the center of the tree stays open. Removing water sprouts and suckers is the most time consuming and difficult practice necessary to bring an overgrown apple back into shape.   (Ward Upham)

Pests:
Check Plants for Scale Insects

scale insects
The dormant season is a good time to check woody plants for scale insect infestations. This time of year, deciduous plants do not have leaves, so scale is more easily seen.
    
If an infestation is detected, make plans to apply a dormant oil 
for control by March 1. Be sure the temperature is 40 degrees or above before spraying. Scale insects are easily overlooked because they are small and immobile most of their lives and they do not resemble most other insects. Many of them resemble small shells that are oval or circular, but some have more unusual shapes like oyster shells. Coloring varies, but can include white, tan, and brown.
    
Plants that should be inspected for scales include apples, pears, 
other fruit trees, bush fruits, lilac, crabapple, oak, ash, elm, lilac, maple, linden, arborvitae, juniper, pine, spruce and yew. Manhattan euonymus, a broadleaf evergreen, is especially noted for having scale problems.  Plants are not harmed if only a few scales are present. But scale population can increase dramatically during the growing season. Heavy scale infestations can damage fruit crops, destroy branches and kill entire plants. (Ward Upham)

Fungus Gnats

Fungus gnat
Fungus gnats are small insects (1/8 to 1/10 inch long) that are common in high-organic-matter houseplant soils that are kept moist. Though adults are mosquito-like in appearance, they do not bother humans or pets. It is actually the larvae or maggots that can injure plants by feeding on the roots. Symptoms include sudden wilting, loss of vigor, poor growth and yellowing leaves. Use of sterile media and avoiding overwatering can help prevent infestations. Existing infestations can be controlled Bacillus thuringiensis v. israelensis (Gnatrol). (Ward Upham)

Contributors:  Ward Upham, Extension Associate

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Horticulture Newsletter 2016, No. 4

1/26/2016

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Video of the Week:
Easy Care Plants

Upcoming Events:

Picture
RetailWorks
February 4, 2016
Manhattan, KS
 
Grow Your Garden Center Business in 2016!
We hope you'll join us for this companion conference to the biennial NurseryWorks conference--RetailWorks on Thursday, February 4, 2016 in Manhattan. While NurseryWorks focuses on providing resources for wholesale nursery crop growers, RetailWorks is designed with the independent garden center's needs in mind. We continue to bring in outstanding national and local speakers on a variety of topics. You'll find great content and networking at RetailWorks 2016--get it on your calendar and register today!  For more information, go to:
http://retailworks.weebly.com/ or register online at https://2016retailworks.eventbrite.com

Fruit:
Late Blooming and Frost Resistant Peach Trees

Peach blossom
Late spring frosts often eliminate potential peach crops in Kansas.  Since hardiness of fruit buds drops dramatically as flower buds open, even a delay in bloom time of a few days can dramatically affect the size of fruit crop.  A study done in southwestern Idaho investigated the average bloom times of a number of peach cultivars from 2003 - 2007.
 
Cultivar                    Date of full bloom
‘Snow Giant’                April 5
‘Jupiter’                        April 7
‘Yukon King’                April 7
‘Burpeach Six’             April 7
‘Fairtime’                      April 7
‘Coral Star’                   April 7
‘July Sun’                     April 7
‘Zee Lady’                    April 7
‘May Sun’                    April 8
‘Crimson Lady’           April 8
‘Summer Flame’         April 8
‘Elegant Lady’             April 8
‘Sugar Giant’               April 8
‘July Flame’                 April 8
‘Sweet Dream’             April 8
‘August Flame’            April 8
‘September Snow’       April 8
‘Snow King’                  April 8
‘Star Fire’                      April 8
‘Saturn’                         April 8
‘August Lady’              April 9
‘Ryan Sun’                    April 9
‘Brenda Sun’                April 9
‘All Star’                       April 9
‘Autumn Red’              April 9
‘O’Henry’                     April 9
‘Opal Moncav’             April 9
‘Rich Lady’                   April 9
‘Vista’                            April 9
‘Glow Star’                   April 9
‘Summer Lady’           April 10
‘Red Star’                     April 11
‘Fancy Lady’                April 12
‘Sierra Gem’                April 12
 
'Intrepid,' though not included in the above study, is a cultivar not only known for its late bloom time but also its frost-resistant blooms.  A study done in North Carolina noted that exposure to 6 consecutive subfreezing nights at 50% bloom did not eliminate the fruit crop.  All flower buds on all check cultivars were killed. (WU)

Cloning Apple Trees

Apple tree graft
We occasionally receive calls from gardeners who want to know how to treat an apple seed so it will germinate. Usually, the gardener is trying to reproduce an old apple tree that was special for some reason (good quality fruit, planted by grandparents, etc.).  Unfortunately, apples grown from seed will not be like the parent. About 1 in every 80,000 apple trees grown from seed will be as good as the apples we are used to eating. Apple trees grown from seed usually have small and inferior quality fruit.
 
If you want a tree exactly like the parent, you must propagate that tree vegetatively. In the case of apples, this usually means grafting. Apple trees are actually quite easy to graft, even for novices. Don't be afraid to try even if you haven't grafted before. The step that needs to be done at this time of year is the choosing and cutting of scion wood or small branches that will be grafted on top of a rootstock.
 
See the accompanying article in this newsletter on how this is done. However, if you don’t have an existing tree to graft onto, you will need to plant a rootstock this year for grafting onto next. Fruit trees are normally grafted (or budded) onto specially selected rootstocks. These rootstocks usually reduce tree size. For example, a tree that normally would reach 25 feet tall will only reach 10 feet if it is grown on a certain rootstock. Dwarfing rootstocks also allow apples to bear fruit a year or more earlier.
 
A tree on its own roots normally takes 5 to 7 years before it will bear. Semi-dwarf trees bear in 4 to 5 years, and dwarf trees bear in 3 to 4 years. Unfortunately, not all dwarfing rootstocks are well adapted to Kansas. Semi-dwarf trees usually are a better choice for us. Note that rootstock reduces tree size, not fruit size. Therefore, a Golden Delicious tree that only reaches 8 feet tall due to a dwarfing rootstock, will bear the same size fruit as a Golden Delicious tree that is 25 feet tall.
 
Most nurseries only sell trees that are already grafted. A company that does sell rootstocks is Raintree Nursery, Morton, WA, (360) 496-6400, http://www.raintreenursery.com/Rootstocks/ Another is Cummins Nursery, 865- 233-3539, http://www.cumminsnursery.com/rootstocks.htm though there is a minimum shipping and handling fee of $20.
 
It is also possible to buy a tree from a local nursery and graft your clone into it. This will give you one tree that produces two different apples. One disadvantage of this method is that it is possible to prune off the special clone by mistake in later years.

This information does not include the details of grafting or budding or subsequent care.  The Missouri Extension Service has an excellent publication on grafting at http://extension.missouri.edu/explorepdf/agguides/hort/g06971.pdf   as well as a second publication on budding at http://extension.missouri.edu/explorepdf/agguides/hort/g06972.pdf . Be sure to practice your cuts on wood you prune off in March. After you do about 100 cuts, you will start to get the hang of it. (Ward Upham)

Vegetables:
Using a Planting Calendar

Seed starting
If you start vegetable plants indoors, it is often helpful to list seeding dates on a calendar so that plants are ready for transplanting at the proper time. To do this, choose your transplant date and count back the number of weeks necessary to grow your own transplants. For example, cabbage, broccoli, and cauliflower are usually transplanted in late March to early April. It takes 8 weeks from seeding to transplant size.
 
Plants should be seeded in early February. Information on how many weeks it takes to grow transplants is available in our January 6 newsletter at  http://www.hfrr.ksu.edu/doc4036.ashx
 
Below are examples of some common vegetables grown for transplants and a recommended date for seeding. Dates are Saturdays as this is when many homeowners have the most free time. The dates are not set in stone, and a week earlier or later will not ruin the plants. Also, you may want to seed a week or two earlier if you are in southern Kansas and possibly a week later if you are in northern Kansas. Keep notes on how well the transplants did so you can tweak the
planting schedule. Your conditions may result in plants that need a bit more or a bit less time. (Ward Upham)
 
Crop                                                      Seeding Date        Transplant Date
Cabbage, broccoli, cauliflower        February 6            April 2
Lettuce (if your grow transplants) February 6            April 2
Peppers                                                March 19               May 14
Tomatoes                                             March 26              May 7

Flowers:
Miniature Roses

Miniature Rose
Miniature roses are dwarf versions of roses including the classic hybrid teas. Though they are much smaller (12 to
15 inches tall or less), they are surprisingly tough and can be planted outside where they will survive our Kansas winters if mulched. However, many gardeners like to grow the miniatures indoors where they can enjoy them during the drab winter months.

Miniature roses grown as houseplants have specific requirements. For long lasting flowers, air should be moist with a relative humidity of 50 to 60 percent preferred though 40 percent is adequate. Placing the pots on a tray that holds moist pebbles will help provide the humidity needed.
 
Like most plants, roses need a lot of light in order to flower. Though miniature roses will survive in a south window, many people will supplement available light with fluorescent lamps. Timers can be used to automatically turn the lights on and off. Providing 14 hours of light per day will be plenty for roses to grow and flower. Lights are normally spaced 3 to 4 inches above the tops of the plants.
 
Probably the most serious pest of these plants indoors is spider mites. These mites are very small but can devastate miniature roses. They like dry, warm conditions. Maintaining adequate relative humidity levels and washing the plants once a week in tepid water will help prevent problems. If mites do develop, try using an insecticidal soap or horticultural oil (2 percent rate) for control. The horticultural oil will probably be more effective than the soap. Be sure to spray or wash the entire plant including the underside of the leaves so that all mites are contacted.
 
Miniature roses can be placed outdoors during the summer to take advantage of higher light levels. Do not place the plant in full sun immediately but gradually grant more light over a period of several weeks. Pots sunk in the ground will not need to be watered as often as those exposed. Turn the pot 180 degrees every couple of weeks to break off any roots that escape the pot and move into the underlying soil.
 
Miniature roses are not the easiest plants to grow as houseplants but can be well worth the effort required. (Ward Upham)

Miscellaneous:
Plants Recommended for Kansas

Petunia
If you have had trouble finding a listing of plants recommended for Kansas, visit our web page devoted to this topic. We have links to a wide variety of plants including annual flowers, perennial flowers (including breakouts for iris and daylilies), fruit, vegetables, turfgrass, low-maintenance roses and tree recommendations that are broken out by areas of the state. We also list recommended low water use plants. You can find this page at http://www.hfrr.ksu.edu/p.aspx?tabid=731
 
We also have images of hundreds of the following:
 
Varieties of iris and daylilies found in the University Gardens Collection Gardens at http://www.ksre.ksu.edu/ksugardens/p.aspx?tabid=38
 
Annual flowers recommended for Kansas at  http://www.prairiestarflowers.com/Prairie_Star_nav.html
 
Perennial flowers at  http://www.prairiestarflowers.com/Prairie_Bloom_nav.html   (Ward
Upham)
 
Contributors:  Ward Upham, Extension Associate

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Horticulture Newsletter 2015, No. 34

8/25/2015

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Video of the Week:
Overseeding Your Lawn

Turfgrass:
Power Raking and Core-Aeration

core aerator
September is the optimum time to power rake or core-aerate tall fescue and Kentucky bluegrass lawns. These grasses should be coming out of their summer doldrums and beginning to grow more vigorously. This is a good time to consider what we are trying to accomplish with these practices.

Power raking is primarily a thatch control operation. It can be excessively damaging to the turf if not done carefully. For lawns with one-half inch of thatch or less, I don’t recommend power raking but rather core aeration. For those who are unsure what thatch is, it is a springy layer of light-brown organic matter that resembles peat moss and is located above the soil but below the grass foliage. Power raking pulls up an incredible amount of material that then must be dealt with by composting or discarding.

Core-aeration is a much better practice for most lawns. By removing cores of soil, core-aeration relieves compaction, hastens thatch decomposition, and improves water, nutrient, and oxygen movement into the soil profile. This operation should be performed when the soil is just moist enough so that it crumbles easily when worked between the fingers. Enough passes should be made so that the holes are spaced about 2 to 3 inches apart. Ideally, the holes should penetrate 2.5 to 3 inches deep. The cores can be left on the lawn to decompose naturally (a process that usually takes two or three weeks, depending on soil-type), or they can be broken up with a power rake set just low enough to nick the cores, and then dragged with a section of chain-link fence or a steel doormat. The intermingling of soil and thatch is beneficial to the lawn.  (Ward Upham)

Turf in Shade

turf in shade
We are often asked, “What’s the best shade grass for Kansas?” The answer is simple but requires explanation. Tall fescue is the best shade grass for Kansas. That does not mean that tall fescue is the best shade grass of all those grown. True fine leaf fescues such as sheep’s fescue, hard fescue, and creeping red fescue are actually better adapted to shade than tall fescue, but they have difficulty surviving Kansas summers. It might be better to say that tall fescue is the best shade grass adapted to Kansas conditions. Although tall fescue is our best shade grass, that does not mean that tall fescue is all that good in the shade. Large trees that produce deep shade will not allow tall fescue to survive over the long term. I say “over the long term” because fall-planted cool-season grasses will often do well under shade trees through the fall and spring when there is less leaf cover and growing conditions are better (cooler and moister) than in the summer. We often see people plant tall fescue in the shade each fall and then wonder what happens the following summer. The answer is stress from multiple fronts. Sunlight that passes through the leaves of trees has had most of the “good” light that drives photosynthesis stripped out. The grass struggles to make the food it needs for survival and growth. When this poor diet is combined with the additional stresses of drought and heat, tall fescue is unable to survive.

So, what should you do if you have too much shade for your turf? You have three choices. Reduce the shade by pruning up the lower branches of your trees so more early and late sun reaches the turf. This is not practical with many trees because it can destroy the desired shape. A second option is to plant a groundcover that is well-adapted to shady sites such as periwinkle or English ivy. Another solution would be to mulch the area under the tree. (Ward Upham)

Fruit:
Small Peaches

small peach
Late frosts that kill peach flowers are common in Kansas. Many areas will not have a full peach crop except for about one in every seven (or more) years. This year has been exceptional, with full fruit crops and excellent peach-growing weather in most areas. However, we have been receiving reports of trees with small peaches. Though small fruit could be due to poor weather (rare this year) or heavy fruit crops (common), there is a third possibility that is often overlooked. That possibility occurs when the top portion of the peach dies and the rootstock puts up new growth.

Peaches, like other fruit plants, must be vegetatively propagated. In other words, you cannot grow fruit from seed and expect the progeny to share the same characteristics as the parent. Therefore, good fruit trees have a top portion called the scion (the good fruiting part) and a bottom portion known as the rootstock. This combination is made by grafting or budding the scion onto the rootstock. Virtually everything above ground will be the scion and everything below ground will be the rootstock. The rootstock may keep the tree smaller, be more disease resistant than the scion, delay bloom or give some other good characteristic to the tree. However, the rootstock normally does not produce good, high quality fruit. Therefore, if the scion dies and the rootstock throws up new growth, the fruit produced will most likely be of poor quality.

How do you tell if the small fruit is due to a rootstock taking over? If the fruit produced is always poor quality, then suspect the rootstock problem. If this is the case, there is no remedy. The tree will not produce good quality fruit regardless of the care given. It would be best to remove and replace the tree. (Ward Upham)

Flowers:
Peonies May Be Cut Back Now

peonies browning
Peonies often look a little bedraggled by this time of year and gardeners may want to cut them back. That will not be a problem with this perennial. Peonies are essentially dormant by September 1, even though leaves may still be green. Cut leaves off close to the ground and compost or discard. (Ward Upham)

Ornamentals:
Spring Flowering Shrubs

spring flowering shrub Forsythia
August through September is the time period our spring flowering shrubs set flower buds.  Therefore, watering, as needed, at this time can help with next spring’s bloom.  Examples of spring flower shrubs include Forsythia, Flowering Quince, Almond, Beautybush, Deutzia, Pyracantha, Lilac, Mock Orange, Cotoneaster, Weigela, Viburnum and Witchhazel.  (Ward Upham)

Mycosphaerella Leaf Spot on Ash

Mycosphaerella leaf spot on ash
With all the concern about Emerald Ash Borer (EAB), many people may assume the trees are being attacked by EAB. However, EAB has only been confirmed in Johnson, Leavenworth and Wyandotte counties. 

Mycosphaerella leaf spot causes small, brown spots that enlarge to become blotches and may result in early leaf drop. Though this disease looks serious, it is not. Defoliation this late in the growing season will not hurt the health of the tree. Therefore, because this disease appears sporadically and tree health is not harmed, we do not recommend treatment. Furthermore, treatment would have to be preventative and applied before the disease had infected the leaves. Applying a fungicide now would have no effect. (Ward Upham)

Pests:
Fall Webworm

fall webworms
On a return trip to Manhattan Monday, I noted the presence of fall webworms along the roadway --- sometimes one or two in an occasional tree here and there, or (in this instance) numerous web masses.  These did not develop “overnight.” Judging by their size, these colonies likely were initiated 4-5 weeks earlier. People may worry about the impact of feeding depredations, but it is minimal. A healthy tree will not be hurt.  Probably a more verbally expressed concern is the unsightliness created by the webbing, as well “creepy” clumps of caterpillars within.

A common recommendation is to prune out webbed branches. One must consider the accessibility of web masses --- those beyond reach simply allowed to remain. Pruning might be doable if just a branch or two ---- but possibly unacceptable and disfiguring when trees are heavily infested with web masses.If within reach, consider an implement (of sorts) to “rake out”/remove webbing. And what implement could be more handy (yes, pun intended) than one’s own hand. There is no need to fear the dry webbing and/or dried fecal deposits and squirmy caterpillar within. As webbing is removed, also removed will be the objectionable dead/dry foliage and the fall webworms. Simply dispose of the gathered material. All that is left behind is the leafless (but still living) branch and its’ intact buds which will produce the ensuing year’s foliage.  (Bob Bauernfeind)

Contributors: Ward Upham, Extension Associate; Bob Bauernfeind, Extension Entomologist

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    Ward Upham runs the Horticulture Response Center in the Department of Horticulture and Natural Resources at Kansas State University. Other contributors include K-State Extension Specialists.

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