Category: Cool Season Vegetables

Hardiness of Cool-Season Vegetables

10/11/2017

Cool-season vegetables vary in cold tolerance, with some able to take colder temperatures than others. Semi-hardy crops can take a light frost but are damaged by temperatures in the mid- to upper-20s. Examples include beets, Chinese cabbage, collards, Irish potatoes, Bibb lettuce, mustard, radishes, spinach, Swiss chard, and leaf lettuce. Covering these plants when cold weather threatens can help extend the harvest season.

Plants termed “hardy” can take lower temperatures but are damaged when the temperature drops to the low 20s. These include cabbage, broccoli, cauliflower, Brussels sprouts, carrots, turnips, and kale.

Certain root crops can essentially be stored outside even after the leaves have been damaged or killed by frost. Beets, carrots, potatoes and turnips can be mulched and harvested as needed until the soil starts to freeze in late November to December.

Growing vegetables in Kansas can be a challenge, but we have an extremely long gardening season. We can harvest from early April (asparagus) to early December. Winter is a good time to plan and prepare for next year’s crops. (Ward Upham)

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Vegetables: Fertilizing Cole Crops

4/18/2017

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If you planted cole crops such as cabbage, broccoli and cauliflower earlier this spring, they will need a little fertilizer boost. These plants need to mature before summer heat arrives, so they must grow quickly while the weather is cool. A sidedressing of fertilizer about 3 weeks after transplanting helps plants continue to grow rapidly.

Use fertilizers high in nitrogen for sidedressing such as nitrate of soda or blood meal at the rate of 2 pounds per 100 feet of row. You may also use lawn fertilizers that have close to 30 percent nitrogen such as a 30-3-4 or 29-5-4 but the rate should be cut in half to 1 pound per 100 feet of row. Do not use lawn fertilizers that have weed killers or preventers. Fertilizer must be watered in if timely rains don't do that job for you.

We have a sheet available that gives recommendations on how to sidedress specific vegetable crops. It can be found at: https://tinyurl.com/j2ggaa6    (Ward Upham)

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Vegetables: Frost Proof Vegetable Plants

3/20/2017

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Certain vegetables can withstand cold spring temperatures as long as they have been toughened up by gradually exposing them to sunlight and outdoor temperatures. This “hardening off” process usually takes about a week.

Reducing watering and temperature is the key to toughening up transplants. If possible, move transplants outside for a portion of each day. Start by placing them in a shady, protected location and gradually move them into a more exposed, sunny location as the week progresses. Hardened off cabbage, broccoli, cauliflower and onions can withstand temperatures near 20 F without being killed. Lettuce plants are not quite as tough but will be okay if exposed to temperatures in the mid 20s.

Don’t hesitate to put these plants out now if extreme cold is not forecast. (Ward Upham)

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Horticulture Newsletter 2016, No. 42

10/18/2016

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Video of the Week:
Storing Tender Bulbs for the Winter

Upcoming Events:

Kansas Turfgrass Conference in conjunction with KNLA December 6,7 & 8, 2016

Mark the date to attend the Kansas Turfgrass Conference in conjunction with KNLA on December 6, 7 & 8 in Topeka.

The conference is an excellent way to learn about turf, nursery and landscape management, visit with old friends, network with new ones, and see all the latest equipment and supplies from local and national vendors.

The conference has been approved for Commercial pesticide recertification hours:
1 Core hour       3A - 8 hrs           3B - 9 hrs

International Society of Arboriculture CEUS and GCSAA education points will also be available by attending the conference.

Download a copy of the program, get exhibitor information, or register online
      http://2016ktf.eventbrite.com

Turfgrass:
Control Broadleaf Weeds in Lawns in Late October - Early November

Late October to early November is the most effective time to control broadleaf weeds in lawns. Dandelions usually produce a flush of new plants in late September, and the winter annual weeds henbit and chickweed should have germinated in October. These young plants are small and easily controlled with herbicides such as 2,4-D or combination products (Trimec, Weed-B-Gon, Weed-Out) that contain 2,4-D, MCPP and Dicamba. Even established dandelions are more easily controlled now than in the spring because they are actively moving materials from the top portion of the plant to the roots in the fall.

Herbicides will translocate to the roots as well and will kill the plant from the roots up. Choose a day that is 50 degrees or higher. The better the weed is growing, the more weed killer will be moved from the leaves to the roots. Cold temperatures will slow or stop this process.

Weed Free Zone (also sold under the name of Speed Zone) contains the three active ingredients mentioned above, plus carfentrazone. It will give a quicker response than the other products mentioned especially as temperatures approach 50 degrees. (Ward Upham)

Why Late Lawn Seedings Often Fail

We normally recommend that Kentucky bluegrass and tall fescue be seeded in September but no later than October 15. Though plantings later than October 15 can be successful, the odds of success diminish as time passes.

The problem with late plantings is not that the seed will not come up or that young grass plants are sensitive too cold. Most often, the problem is with rooting. Unless the young grass plants have a fairly extensive root system, the freezing and thawing that takes place during winter heaves plants out of the ground, and they dry out and die.

Regardless of when planted, be sure the new lawn is kept watered through the fall. More mature lawns will need less frequent watering but all should go into the winter with moist soil. (Ward Upham)

Tucking Your Lawnmower in for the Winter

If you are done mowing for the year, be sure to service your mower before putting it away. Make sure you drain the gas tank of gasoline-powered engines or use a gasoline stabilizer. Untreated gasoline can become thick and gummy. A few drops of oil squirted inside the spark plug hole (after you remove the spark plug) will help lubricate the cylinder. While you have the spark plug removed, replace it with a new one. If your equipment has a battery, clean the battery terminals, which usually corrode during the season. A wire-bristle brush is a good tool for doing this. The battery can then be removed or connected to a battery monitor that will keep it charged over winter. If you remove the battery, be sure to store it in a protected location for the winter (a cool basement works best). Now is also an excellent time to sharpen mower blades so they'll be ready next spring.

Sharpening rotary mower blades is fairly straightforward. The following steps will guide you through this process:
      * Check the blade for major damage. If you can't fix it, it likely will need to be replaced.
      * Remove grass and debris from the blade with a moist cloth. Dry before beginning to sharpen the cutting edge.
      * Remove nicks from the cutting edge, using a grinding wheel or hand-file.
* If using a grinding wheel, match the existing edge angle to the wheel. If hand-filing, file at the same angle as the existing edge.
      * Grind or file until the edge is 1/32 inch, about the size of a period.
      * Particularly with a grinding wheel, avoid overheating the blade as this may warp it.
      * Clean the blade with solvent or oil, much like if you were cleaning a gun, for optimum winter storage. Avoid using water because it will promote rust.

Following these tips can help you better prepare your mower for winter storage and also save you some steps this coming spring. (Ward Upham)

Vegetables:
Hardiness of Cool-Season Vegetables

Ornamentals
"Apples" on an Ornamental Shrub

We have had a number of reports of misshapen or fuzzy “apples” developing on a thorny shrub in the landscape. This is most likely flowering quince. Flowering quince is grown for its attractive blooms in the spring. Normally fruit does not develop because frosts prevent fruit formation and plants fruit poorly without cross-pollination. Quince fruit are quite hard but are sometimes mixed with other fruit to make jellies and preserves. (Ward Upham)

Contributors: Ward Upham, Extension Associate

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Horticulture Newsletter 2016, No. 12

3/22/2016

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Video of the Week:
Caring for Knockout Roses

Upcoming Events:

Hands-On Mushroom Cultivation Workshop

Friday, April 1 or Saturday, April 2

Topics Covered:
Growing oyster mushrooms on straw and sawdust
Inoculating shiitake mushroom logs (hands-on)
Growing winecap mushrooms in woodchips or straw mulch
Log selection and harvest

Each participant will receive:
Oyster Mushroom Production Bag
Inoculated Shiitake Log

Cost of the workshop: $25

For details, see http://www.reno.k-state.edu/docs/Mushroom%20workshop%20flyer.pdf or call
620-662-2371.

Vegetables:
Frost Proof Vegetable Plants

Asparagus Time

Asparagus is one of those vegetables where freshness is incredibly important. If you have never eaten asparagus fresh out of the garden, try it. It may convince you to grow some of your own. For those who have an asparagus patch, the new spears should be appearing soon. The first asparagus that comes through the ground always seems to take a long time to reach harvest size. That is because asparagus growth is temperature dependent. The higher the day and nighttime temperatures, the faster it grows. Also, the longer the spear, the quicker the growth. As the season progresses and spears get longer, the growth rate increases.

Harvest asparagus by snapping or cutting. Snapping is quick and easy. Simply bend the stalk near the base until it breaks. Snapped ends dry quickly so refrigerate or use soon after harvest. If you cut asparagus, use a sharp knife to detach the spears slightly below ground level. This base is woodier than snapped asparagus, so it doesn't lose water as quickly. Cut off woody ends before cooking. (Ward Upham)

Herbicides for Home Gardens

Though mulches and hoeing are usually all that is needed for small vegetable gardens, homeowners with large areas may need the help of herbicides to keep ahead of the weeds. One preemergence and one postemergence herbicide can be used on home vegetable gardens.

The preemergence herbicide is trifluralin. Preemergence herbicides kill weed seeds as they germinate. They usually have no effect on weeds that have emerged. Therefore, they must be put on either before weeds come up in the spring or after weeds have been physically removed. The preemergence herbicide trifluralin is sold under the trade names of Treflan, Preen, Miracle-Gro Garden Weed Preventer, Gordon's Garden Weed Preventer Granules and Monterey Vegetable and Ornamental Weeder.

The postemergence herbicide is sethoxydim. This product only kills grasses; broadleaves are not affected. It can be sprayed directly over the top of many vegetables. Sethoxydim is sold as Poast, Monterey Grass Getter, and Hi-Yield Grass Killer. A second postemergence herbicide called fluazifop-p-butyl is labeled for commercial growers as Fusilade, but I haven't found vegetables listed on the homeowner labels, “Over the Top Grass Killer” and “Grass-No-More.” Also, the other homeowner products mentioned above often do not have as many vegetables on the label as the commercial products. Even among the homeowner products with the same active ingredient, there may be slight differences among labels. Check product labels to be sure the crop is listed. Here is a list of herbicides and the crops for which they are labeled. Many of these crops have application restrictions. For example, trifluralin can be used on asparagus, but must be applied before spears emerge. (Ward Upham)

Fruit:
Apple Tree Sprays

Two common diseases on apple trees are cedar apple rust and apple scab. Though some apple varieties are resistant to these diseases — including Liberty, Jonafree, Redfree, Freedom, Williams Pride and Enterprise — most varieties are susceptible. For a listing of the disease resistance of various cultivars, go to: http://extension.missouri.edu/explorepdf/agguides/ hort/g06022.pdf

Fungicide sprays during April and May are critical to preventing disease on susceptible varieties. With the warm spring this year, we may have to start sprays in March. The first spray should go down when leaves appear. A fungicide that is available to homeowners and very effective for control of apple scab and cedar apple rust is myclobutanil (Immunox). There are several formulations of Immunox but only one is labeled for fruit. Check the label.

Sprays should be done on a 7- to 10-day schedule to keep the protective chemical cover on the rapidly developing leaves and fruit. An insecticide will need to be added to this mixture after petal drop to prevent damage from codling moths that cause wormy apples. Methoxychlor or malathion can be used as an insecticide. In order to protect bees, DO NOT use any insecticide during bloom. Check the malathion label before purchase as not all labels list fruit.

Although gardeners may continue to use myclobutanil throughout the season, certain other fungicides are more effective on summer diseases such as sooty blotch and fly speck. Consider switching to Captan or to a fruit spray mixture about June 1. A spreader-sticker can be added to the fungicide-insecticide chemical mixture to improve the distribution and retention of the pest control chemicals over the leaves and fruit. A hard, driving rain of about 1 inch or more will likely wash chemicals from the leaves and fruit. In such cases, another application should be made. You can find information on controlling insects and diseases on fruit trees in our publication titled "Fruit Pest Control for Home Gardens" at http://www.ksre.ksu.edu/bookstore/pubs/c592.pdf Below is the spray schedule I use. Sprays are applied ever 10 days until 2 weeks before harvest.

Leaves Appear: Immunox
Petal Drop: Add malathion to the Immunox and so the mixture is Immunox + malathion
June 1: Replace Immunox with Captan. The mixture is now Captan + malathion

Stop spraying 2 weeks before harvest. (Ward Upham)

Turfgrass:
Core Aeration of Cool-Season Grass

If you are planning to core-aerate your tall fescue or Kentucky bluegrass lawn this spring, March or early-April is the time. Coring early in the spring gives cool-season lawns a chance to recover before crabgrass and other warm-season annual weeds start to germinate.

Core-aerating is one of the best things you can do for your lawn. It relieves compaction, hastens thatch decomposition, increases water infiltration and helps promote better root growth. Pay attention to the soil moisture level when coring. The soil should easily crumble when worked between the fingers. If it is too wet, the machine's tines will plug and it will merely punch holes in the wet soil, which increases compaction. If it is too dry, the tines will not be able to penetrate deeply enough to be of benefit. (Ward Upham)

Ornamentals:
Hackberry Psyllid, the Tiny "Gnat" Invading Homes

It is rare to find a hackberry tree without round growths on the underside of the leaves. These bumps, or galls, are the result of a tiny insect known as the hackberry psyllid. Hackberry is the only known host of this pest.

The adults of these insects are tiny and resemble miniature cicadas. They are dark reddish-brown with mottled wings. Most emerge from the galls during warm days in September and are very annoying as they gather around window screens seeking entry into the house. They are tiny enough to crawl through the openings in most screens. In the spring, the adults become active about the time the leaf buds open. The female lays her eggs on the underside of the developing leaves. Egg hatch occurs in 7 to 10 days, and the young nymphs begin to feed immediately. The leaf reacts to the feeding by producing a pouch or gall that entirely encloses the nymph.

Control is difficult. Adults that invade homes can be collected by using a vacuum sweeper but the bag should be discarded or the adults will escape. Since these insects do not seriously affect the vitality of the hackberry tree, control is usually not recommended. (Ward Upham)

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Horticulture Newsletter 2015, No. 42

10/20/2015

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Video of the Week:
Storing Tender Bulbs for Winter

Turfgrass:
Control Broadleaf Weeds in Lawns in Late October - Early November

Late October to early November is the most effective time to control broadleaf weeds in lawns. Dandelions usually produce a flush of new plants in late September, and the winter annual weeds henbit and chickweed should have germinated in October. These young plants are small and easily controlled with herbicides such as 2,4-D or combination products (Trimec, Weed-B-Gon, Weed-Out) that contain 2,4-D, MCPP and Dicamba. Even established dandelions are more easily controlled now than in the spring because they are actively moving materials from the top portion of the plant to the roots in the fall. Herbicides will translocate to the roots as well and will kill the plant from the roots up.

Choose a day that is 50 degrees or higher. The better the weed is growing, the more weed killer will be moved from the leaves to the roots. Cold temperatures will slow or stop this process.

Weed Free Zone (also sold under the name of Speed Zone) contains the three active ingredients mentioned above, plus carfentrazone. It will give a quicker response than the other products mentioned especially as temperatures approach 50 degrees. (Ward Upham)

Tree Leaves and Turf

It's that time of year again. Leaves are rapidly falling from deciduous trees so it's a good time to stop and think about options for handling the litter. Although a scattering of leaves won’t harm the lawn, excessive cover prevents sunlight from reaching turfgrass plants.

Turf left in this state for an extended period will be unable to make the carbohydrates needed to carry it through the winter.

There are options for dealing with the fallen leaves other than bagging them up and putting them out for the trash collector. Composting is a great way to handle the refuse. Compost can then be used in the vegetable garden and flowerbeds. If you do not compost, you can mow leaves with a mulching mower and let shredded leaves filter into the turf canopy. (A side-discharge mower also will work, but it won't shred the leaves as thoroughly.) This method will be most effective if you do it often enough that leaf litter doesn’t become too thick. Mow while you can still see grass peeking through the leaves.

You may wonder whether this practice will be detrimental to the lawn in the long run. Research at Michigan State University in which they used a mulching mower to shred up to about one pound of leaves per square yard of lawn (one pound is equal to approximately 6 inches of leaves piled on the grass) for five consecutive years, found no long-term effects of the shredded leaves on turf quality, thatch thickness, organic content of the thatch, or soil test results (pH, nutrients, etc.). If you mow leaves and have a cool-season lawn, it makes sense to be on a fall nitrogen fertilization program and core-aerate in the fall (things you should be doing anyway). If you have a warm-season lawn, you can still use this technique but wait to fertilize and core-aerate until next late May or early June. (Ward Upham)

Tucking Your Lawnmower in for the Winter

If you are done mowing for the year, be sure to service your mower before putting it away. Make sure you drain the gas tank of gasoline-powered engines or use a gasoline stabilizer. Untreated gasoline can become thick and gummy. A few drops of oil squirted inside the spark plug hole (after you remove the spark plug) will help lubricate the cylinder. While you have the spark plug removed, replace it with a new one. If your equipment has a battery, clean the battery terminals, which usually corrode during the season. A wire-bristle brush is a good tool for doing this. The battery can then be removed or connected to a battery monitor that will keep it charged over winter. If you remove the battery, be sure to store it in a protected location for the winter (a cool basement works best).

Now is also an excellent time to sharpen mower blades so they'll be ready next spring. Sharpening rotary mower blades is fairly straightforward. The following steps will guide you through this process:
        * Check the blade for major damage. If you can't fix it, it likely will need to be replaced.
        * Remove grass and debris from the blade with a moist cloth. Dry before beginning to sharpen the cutting edge.
        * Remove nicks from the cutting edge, using a grinding wheel or hand-file.
        * If using a grinding wheel, match the existing edge angle to the wheel. If hand-filing, file at the same angle as the existing edge.
        * Grind or file until the edge is 1/32 inch, about the size of a period.
        * Particularly with a grinding wheel, avoid overheating the blade as this may warp it.
        * Clean the blade with solvent or oil, much like if you were cleaning a gun, for optimum winter storage. Avoid using water because it will promote rust.

Following these tips can help you better prepare your mower for winter storage and also save you some steps this coming spring. (Ward Upham)

Vegetables:
Hardiness of Cool-Season Vegetables

Cool-season vegetables vary in cold tolerance, with some able to take colder temperatures than others. Semi-hardy crops can take a light frost but are damaged by temperatures in the mid- to upper-20s. Examples include beets, Chinese cabbage, collards, Irish potatoes, Bibb lettuce, mustard, radishes, spinach, Swiss chard, and leaf lettuce. Covering these plants when cold weather threatens can help extend the harvest season. Plants termed “hardy” can take lower temperatures but are damaged when the temperature drops to the low 20s. These include cabbage, broccoli, cauliflower, Brussels sprouts, carrots, turnips, and kale.

Certain root crops can essentially be stored outside even after the leaves have been damaged or killed by frost. Beets, carrots, potatoes and turnips can be mulched and harvested as needed until the soil starts to freeze in late November to December.

Growing vegetables in Kansas can be a challenge, but we have an extremely long gardening season. We can harvest from early April (asparagus) to early December. Winter is a good time to plan and prepare for next year’s crops. (Ward Upham)

Winter Mulching of Vegetables

We can extend the harvest season of some root crops such as beets, carrots, parsnips, and turnips by mulching to slow down soil freezing. Mulching allows harvest to continue much later than usual (usually mid- to late-December) when even mulched areas freeze hard.

Rhubarb is a shallow-rooted perennial crop that can also benefit from mulching to help stabilize soil temperatures. Plants that are not mulched may be heaved out of the ground by alternate freezing and thawing through the winter. Mulching moderates these temperature shifts and helps protect the plant. Mulch should be removed by mid-March so soil warming can encourage early emergence. (Ward Upham)

Ornamentals:
Natural Needle Drop on Conifers

We are starting to see very noticeable natural needle drop on some evergreens such as pines and spruce. This is a process where 2- to 4-year-old interior needles turn yellow, then brown, and eventually drop off. Those who aren't familiar with this process often are concerned about the health of the tree. This is a natural phenomenon that occurs every year and does not hurt the tree.

However, some years it is much more noticeable than others. Be sure to check that only the older needles are affected --the needles on the tips of the branches should look fine--and that there is no spotting or banding on the needles that are turning yellow. If spotting or banding is noted, take a sample to your local county extension office for diagnosis. (Ward Upham)

My Oaks are Raining Worms

Areas near Wichita, Kansas is receiving calls regarding tiny, white worms falling from pin oak trees. These worms are actually the larvae of the oak vein gall midge. A midge is a very small fly and therefore the larvae are maggots.

The larvae came from the vein galls that are on the pin oak leaves. Newly hatched larvae feed on the veins of young leaves in the spring and cause a swelling and flattening of the veins. These maggots are now dropping to the ground in order to pupate. Adults emerge early the next spring to start the cycle all over again. The midges apparently cause no damage. (Ward Upham)

Miscellaneous:
Why No Black Walnuts This Year?

Many areas of Kansas have noticed a lack of black walnut nuts this year. This can be traced back to the sharp drop in temperature last fall in which we had a high of 69 degrees on November 10, 2014 followed by a low of 19 the next morning. Unfortunately, our walnut trees had not hardened off sufficiently by November 10 to protect the flower buds.

Black walnut flower buds are formed during the summer of the year before they bear. Therefore, what should have been this year’s nut crop set flower buds during the summer of 2014. When the temperature dropped so quickly in November, the flower buds were damaged resulting in no nuts this year. However, areas of Kansas that have seen plentiful rains, should have a good walnut crop next year unless we have another sharp drop in temperature before the trees have hardened off. (Ward Upham)

Contributors: Ward Upham, Extension Associate

To view Upcoming Events: http://tinyurl.com/fswqe

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Horticulture Newsletter 2015, No. 11

3/17/2015

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Video of the Week:
Pruning Fruit Trees

Turfgrass:
Core Aeration of Cool-Season Lawns

If you are planning to core-aerate your tall fescue or Kentucky bluegrass lawn this spring, reserve a machine now so you can get the job done in March or early-April. Coring early in the spring gives cool-season lawns a chance to recover before crabgrass and other warm-season annual weeds start to germinate.

Core-aerating is one of the best things you can do for your lawn. It relieves compaction, hastens thatch decomposition, increases water infiltration and helps promote better root growth. Pay attention to the soil moisture level when coring. The soil should easily crumble when worked between the fingers. If it is too wet, the machine's tines will plug and it will merely punch holes in the wet soil, which increases compaction. If it is too dry, the tines will not be able to penetrate deeply enough to be of benefit. (Ward Upham)

Vegetables:
Frost Proof Vegetable Plants

Certain vegetables can withstand cold spring temperatures as long as they have been toughened up by gradually exposing them to sunlight and outdoor temperatures. This “hardening off” process usually takes about a week. Reducing watering and temperature is the key to toughening up transplants. If possible, move transplants outside for a portion of each day. Start by placing them in a shady, protected location and gradually move them into a more exposed, sunny location as the week progresses. Hardened off cabbage, broccoli, cauliflower and onions can withstand temperatures near 20 F without being killed. Lettuce plants are not quite as tough but will be okay if exposed to temperatures in the mid 20s. Don’t hesitate to put these plants out now if extreme cold is not forecast. (Ward Upham)

Controlling Weeds in Home Garden Asparagus Beds

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 Asparagus

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:
Pruning Hybrid-Tea Roses

The best time to prune roses is in the spring before new growth appears and after danger of killing frost. Be sure to remove dead stubs. Otherwise, canker fungi may invade stubs and progress into healthy tissue during the summer. Use sharp shears and make cuts at a 45-degree angle about a quarter-inch above healthy buds. How much to prune after dead wood removal depends on the type of rose.

For shrub roses, pruning usually consists of removing dead wood or light pruning for shaping. This article focuses on hybrid tea roses which require much more extensive pruning. With hybrid teas, there are three pruning styles, each with a specific purpose. Heavy or severe pruning is done on well-established, vigorous plants to produce large, showy flowers. Prune back to three to four healthy canes with three to six eyes per cane. Canes normally will be 6 to 12 inches long. Moderate pruning is done on well-established, healthy plants and is designed to increase the number of flowers produced rather than increase flower size. Leave five to six healthy canes with at least seven buds per cane. Prune stems to 12 to 18 inches long. Light pruning rejuvenates plants after years of neglect or may be performed on newly established plants. Leave five to seven canes of about 18 inches or more in length. This helps maximize leaf area for energy production and rejuvenates plants.

If your plants suffered a significant amount of winter damage, they may need to be cut back more severely than even the heavy-pruning style. This will result in a few large flowers but in this case is your only option. (Ward Upham)

Ornamentals:
Breaking the Pine Wilt Cycle

Pines have several disease and insect problems. One of them is pine wilt disease. It kills the entire tree quickly.

Pine wilt is caused by the pinewood nematode, a microscopic worm. The nematode is spread by the pine sawyer beetle. The nematode feeds and multiplies in the tree’s resin canals, causing wilting and death in several weeks to several months. The nematode and beetles spend the winter in the infected tree. In spring, the beetles emerge starting around May 1, carrying nematodes to new trees and continuing the cycle of infection.

The disease is common in the eastern half of the state, and it is spreading west around 10 miles per year. There have been pockets of infection in the western part of the state.

In Kansas, new pine wilt infections are most visible from August to December. Trees wilt and die in a short period of time, from several weeks to a few months. In the first stages, the needles turn grey or green, then yellow and brown. The discoloration sometimes occurs branch by branch, sometimes all at once. With pine wilt, eventually the whole tree dies, within a few months. The brown needles stay on the tree for up to a year after the tree has died. Another key symptom is reduced resin. On a healthy tree, sticky resin bleeds from the site of a wound. In contrast, if a tree has pine wilt, the resin is often reduced or absent, and branches become dry or brittle.

There is a website with color photos and descriptions at the following link: http://muextension.missouri.edu/explorepdf/miscpubs/mx0858.pdf

There are images to compare and contrast pine wilt with other pine diseases here: http://www.ksre.ksu.edu/bookstore/pubs/l722.pdf

With the other diseases (tip blight, needle blight) only parts of the tree turn brown. With pine wilt, the whole tree is brown and dead. If you aren’t sure if your tree has pine wilt or something else, contact your local K-State Research and Extension Office or the K-State Diagnostic Lab (clinic@ksu.edu).

If a tree has pine wilt, the tree should be cut down by April 1 to make sure there is time to destroy the wood by May 1, when the beetles start to some out. Cut the tree to the ground—don’t leave a stump. Chip or burn the wood immediately to destroy the beetles and nematodes. Don’t keep pine wood around for firewood. (Megan Kennelly)

Wild Garlic, Wild Onion, and Star-of-Bethlehem

Wild garlic (Allium vineale) and wild onion (Allium canadense) are two closely related plants that can become weed problems in home lawns and landscapes. Though wild garlic and wild onion look much alike, each has an odor that is characterized by its name – wild garlic smells like garlic and wild onion smells like onion. These plants are perennials that can also reproduce by seeds and aerial bulbils. Bulbils form at the top of the stem and are oval and smooth. Wild garlic also reproduces by underground bulb offsets, but wild onion does not. Both species produce a clump of plants that is unsightly in a lawn. Control recommendations are the same though we now have a couple of new additions to our arsenal.

Traditionally we have used 2,4-D or 2,4-D + MCPP + Dicamba (i.e., Trimec, Weed-Out, Weed-B-Gon). These products should be sprayed during March on a day that is at least 50 degrees. Newer products are Weed Free Zone and Speed Zone. Both are combination products that contain a formulation of Trimec plus carfentrazone. These will give a quicker response at cooler temperatures near 50 degrees. A spreader-sticker added to the spray should help any of these products be more effective. At times, the spreader-sticker is already mixed into the weedkiller; no additional amount is needed. These herbicides are also effective on dandelions.

Unfortunately, we have not had a good chemical control for Star-of-Bethlehem. The best products we had were Coolpower (31.3% control) and Turflon Ester (23.8% control). Coolpower is a commercial only product, but Turflon Ester is available to both commercial and homeowner users. But research out of Virginia Tech has improved our outlook. Scientists there did a study in which they gained 96% control of Star-of-Bethlehem one month after treatment by using Quicksilver, a formulation of carfentrazone at the rate of 4 fl. oz/A. Quicksilver is a commercial only product, and therefore is not available to homeowners. However, both Speed Zone and Weed Free Zone contain carfentrazone and would certainly be worth a try if you have this troublesome plant. (Ward Upham)

Contributors: Megan Kennelly, Plant Pathologist; Ward Upham, Extension Associate

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Video of the Week:Storing Tender Bulbs for the Winter

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Vegetables:Hardiness of Cool-Season Vegetables

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Video of the Week:Caring for Knockout Roses

Upcoming Events:

Vegetables:​Frost Proof Vegetable Plants

Asparagus Time

Herbicides for Home Gardens

Fruit:Apple Tree Sprays

Turfgrass:Core Aeration of Cool-Season Grass

Ornamentals:​Hackberry Psyllid, the Tiny "Gnat" Invading Homes

Horticulture Newsletter 2015, No. 42

Video of the Week:Storing Tender Bulbs for Winter

Turfgrass:Control Broadleaf Weeds in Lawns in Late October - Early November

Tree Leaves and Turf

Tucking Your Lawnmower in for the Winter

Vegetables:Hardiness of Cool-Season Vegetables

Winter Mulching of Vegetables

Ornamentals:Natural Needle Drop on Conifers

My Oaks are Raining Worms

Miscellaneous:Why No Black Walnuts This Year?

Horticulture Newsletter 2015, No. 11

Video of the Week:Pruning Fruit Trees

Turfgrass:Core Aeration of Cool-Season Lawns

Vegetables:Frost Proof Vegetable Plants

Controlling Weeds in Home Garden Asparagus Beds

Remove Fern and Fertilize Asparagus

Flowers:Pruning Hybrid-Tea Roses

Ornamentals:Breaking the Pine Wilt Cycle

Wild Garlic, Wild Onion, and Star-of-Bethlehem

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Video of the Week:
Storing Tender Bulbs for the Winter

Turfgrass:
Control Broadleaf Weeds in Lawns in Late October - Early November

Vegetables:
Hardiness of Cool-Season Vegetables

Ornamentals
"Apples" on an Ornamental Shrub

Video of the Week:
Caring for Knockout Roses

Vegetables:
Frost Proof Vegetable Plants

Fruit:
Apple Tree Sprays

Turfgrass:
Core Aeration of Cool-Season Grass

Ornamentals:
Hackberry Psyllid, the Tiny "Gnat" Invading Homes

Video of the Week:
Storing Tender Bulbs for Winter

Turfgrass:
Control Broadleaf Weeds in Lawns in Late October - Early November

Vegetables:
Hardiness of Cool-Season Vegetables

Ornamentals:
Natural Needle Drop on Conifers

Miscellaneous:
Why No Black Walnuts This Year?

Video of the Week:
Pruning Fruit Trees

Turfgrass:
Core Aeration of Cool-Season Lawns

Vegetables:
Frost Proof Vegetable Plants

Flowers:
Pruning Hybrid-Tea Roses

Ornamentals:
Breaking the Pine Wilt Cycle