Squash bugs are the grey, shield-shaped bugs that feed on squash and pumpkin plants. If you have had problems with these insects in the past, you know that they are almost impossible to control when mature. This is because the squash bugs have a hard body that an insecticide has difficulty penetrating. Thus, spraying when the insects are small is important. We are now seeing the nymphs of the first generation. These nymphs will eventually become adults, which will lay eggs that will become the second generation. The second generation is often huge and devastating. Therefore, it is important to control as many squash bugs now as possible.
    
Because squash bugs feed by sucking juice from the plant, only insecticides that directly contact the insect will work. General use insecticides such as permethrin (Bug-B-Gon Multi-Purpose Garden Dust; Green Thumb Multipurpose Garden and Pet Dust; Bug-No-More Yard and Garden Insect Spray; Eight Vegetable, Fruit and Flower Concentrate; Garden, Pet and Livestock Insect Control; Lawn & Garden Insect Killer), malathion, and methoxychlor provide control if a direct application is made to young, soft-bodied squash bugs. This means that you MUST spray or dust the underside of the leaves because this is where the insects live. (Ward Upham)

July 26            K-State Bedding Plant Field Day, Olathe  http://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

Bermudagrass can make a nice lawn if you don't mind its invasiveness and short growing season. But many people dislike both these characteristics. Warm-season grasses, such as bermudagrass, zoysiagrass and buffalograss, green up later than cool-season grasses such as tall fescue and Kentucky bluegrass. They also go dormant earlier in the fall, which can make a lawn unattractive.
 
Bermuda that invades a cool-season lawn will be brown during much of the spring and fall while the tall fescue portion of the lawn is green. Bermuda is much more drought and heat resistant than cool-season grasses, so it will take over a cool-season lawn during the summer months if it is in full sun.
 
So, how do you control bermudagrass that has invaded a cool-season lawn? Research conducted in 1996 showed that glyphosate (Round-up, Kleen-up, Killzall, Kleeraway) is the best herbicide for the job. Glyphosate is a nonselective herbicide and will kill everything— including tall fescue or Kentucky bluegrass. Therefore, you will need to reseed treated areas. In our study, we applied a 2% solution of glyphosate on July 15 and again on August 15 on a bermudagrass plot that was more than 15 years old. More than one year later, we saw no regrowth. Glyphosate works best if bermuda is growing well. The better the bermudagrass is growing, the more chemical is taken up and pushed into the roots. Water and fertilize if needed to get it going.
 
Spray about the middle of July (or when the bermuda is growing well). Use glyphosate (2% solution). Wait two weeks and scalp the lawn (mow as low as possible and remove clippings.) This will prevent dead grass from covering any bermuda that starts to recover. Wait another two weeks and spray again with glyphosate if there is any green. Wait two more weeks and reseed. (Ward Upham)

Heavy fruit loads this season may cause limbs to break if they are not given extra support. As fruits increase in size, the additional weight on individual branches may be substantial. One-inch thick boards can be used to prop up limbs.
 
Here's how. Cut a "V" on the top edge of the board on which the limb will rest so that it doesn't slip off. Long limbs that are heavily loaded with fruit may need a prop in the center and another to support the outer part of the limb. A plastic belt-like material that is about 2 inches wide may also be used. This can be tied to a heavily loaded limb, then to a large diameter limb above for support. Where a large limb is used for support, it is good to have it supporting limbs on opposite sides so the weight is balanced.
 
Another solution is to wrap a tape or belt material around the tree in a spiral to prevent limbs from bending until they break. Heavy twine may be used, but it should be removed when the fruit is picked or soon after so it does not cut into the bark on the limb.
 
Check trees regularly, up to two times a week during the last month the fruit are maturing. You will find additional limbs that need support. Tending to the heavily loaded tree limbs will reduce the number of broken limbs and help keep a balance of the fruiting wood in your tree. Next year, prune long, weak branches back to a side branch to help prevent this problem. (Ward Upham)

The extreme heat and drought can cause some rarely seen phenomenon. Dennis Patton, our Horticulture Agent in Johnson County has had several reports of apparently sound branches breaking out of what appeared to be a healthy trees (primarily oaks) recently. There was an article written by Richard Harris, the author of a standard Arboriculture text that describes this phenomenon. His observations are summarized below.
 
This type of damage has been reported on both landscape and forest trees. The landscape trees were found in irrigated and unirrigated situations.
 
These limbs can be huge; up to 3 feet in diameter. Most often the break occurs 3 to 12 feet from where the branch attaches though at times the branch may break at the attachment. Though breaks do occur in decayed wood, often the broken branch shows no sign of weakness or decay.

No firm explanation of a cause has been established though buildup of pressure within the branch has been noted.  In some cases, the branch seems to explode and then drop. The reason for this pressure buildup is unclear though several ideas have been put forth.
 
Certain species are more susceptible to this condition including oaks, poplars, cottonwood, willows, ash, sycamore and Japanese Pagodatree. You will find more detail in Richard Harris’ article at  http://artistictreeworks.com/harris.html
 
Be cautious around these trees during hot, calm weather. Hopefully, the cooler weather we had last week will reduce the changes of this happening. (Ward Upham)

Hornworms are the largest larval insect commonly seen in the garden. Though usually seen on tomato, they can also attack eggplant, pepper, and potato.
 
The larval stage of this insect is a 3 ½- to 4-inch long pale green caterpillar with five pair of prolegs and a horn on the last segment. The two most common hornworms are the tobacco hornworm (seven diagonal white stripes and, most commonly, a red horn) and the tomato hornworm (v-shaped markings with a horn that is often blue or black).
 
The adult of the tobacco hornworm is the Carolina sphinx moth. The five-spotted hawk moth is the adult of the tomato hornworm. Both moths are stout-bodied, grayish-colored insects with a wing spread of 4 to 5 inches.
 
The larva is the damaging stage and feeds on the leaves and stems of the tomato plant, leaving behind dark green or black droppings. Though initially quite small with a body about the same size as its horn, these insects pass through four or five larval stages to reach full size in about a month. The coloration of this larva causes it to blend in with its surroundings and is often difficult to see despite its large size. It eventually will burrow into the soil to pupate. There are two generations a year.
 
This insect is parasitized by a number of insects. One of the most common is a small braconid wasp. Larva that hatch from wasp eggs laid on the hornworm feed on the inside of the hornworm until the wasp is ready to pupate. The cocoons appear as white projections protruding from the hornworm's body. If such projections are seen, leave the infected hornworms in the garden. The wasps will kill the hornworms when they emerge from the cocoons and will seek out other hornworms to parasitize.
 
Handpicking is an effective control in small gardens. Bt (Dipel, Thuricide), spinosad (Conserve; Borer, Bagworm, Leafminer & Tent Caterpillar Spray; Colorado Potato Beetle Beater Conc; Captain Jack's Dead Bug Brew, Monterey Garden Insect Spray), cyfluthrin (Bayer Vegetable & Garden Insect Spray) and other insecticides may also be used to control hornworms. (Ward Upham)

If you notice leaves disappearing from walnut trees, it may be walnut caterpillars. Walnut caterpillars attack primarily black walnut, pecan, and several species of hickory trees, but may also attack birch, oak, willow, honey locust, and apple trees.
 
Walnut caterpillars overwinter as pupae underground beneath host trees. In late spring, moths emerge and deposit egg clusters on lower leaves. By the end of June, newly emerged and gregarious larvae skeletonize leaves. Larger hairy, brick-red larvae consume greater amounts of leaf tissue, and nearly matured gray larvae devour entire leaves, including petioles.
 
As mentioned earlier, walnut caterpillars are gregarious. In other words, they feed in groups. A single tree may contain several groups.  When disturbed, larvae arch their bodies in what looks like a defensive move. Larvae crowd together on the lower parts of trees to molt and leave an ugly patch of hairy skins. Mature larvae, 2 inches long, descend or drop to the ground where they enter the soil to pupate. A second generation occurs soon, creating the overwintering pupae.
 
Removing leaves with egg masses is an effective way to control walnut caterpillars. This may be impractical with large trees or when too many infested leaves are present. Bands of Tree Tanglefoot pest barrier may be used to snare larvae as they migrate to main branches or the trunk to molt. Insecticides such as spinosad (Conserve; Captain Jack’s Dead Bug Brew; Borer, Bagworm, Leafminer and Tent Caterpillar Spray) permethrin (numerous trade names) malathion or cyfluthrin (Tempo, Bayer Vegetable and Garden Insect Spray) may provide the most practical means of control. (Ward Upham)

There was a study done in 2005 by Ohio State University that compared the effectiveness of various biorational and natural products to more traditional pesticides. Squash bug was one of the insects that was a target organism. What was interesting is that certain products were more effective at different life stages. The researchers compared the effectiveness of products on young nymphs, old nymphs and adults. Following are the results for squash bug:
 
 
 
Life Stage            Most Effective          Moderately Effective                   Least Effective

Young Nymphs        Spinosad                               Carbaryl                                                           Garlic
                                                                                          Pyrethrins                                                       Neem Oil
                                                                                          Permethrin

Old Nymphs              Spinosad                            Permethrin                                                       Pyrethrins
                                                                                                                                                                      Carbaryl

Adults                         Cyhalothrin                        Esfenvalerate                                                  Spinosad
                                      Cyfluthrin                                                                                                         Permethrin
                                      Pyrethrins                                                                                                          Carbaryl
 
Carbaryl - Sevin
Cyfluthrin - Bayer Vegetable & Garden Insect Spray
Esfenvalerate - Monterey Bug Buster II
Cyhalothrin - Bonide Beetle Killer; Spectracide Triazicide
Permethrin - Bonide Eight Garden Dust; Bayer Complete Insect Dust; Hi-Yield Garden, Pet & Livestock Dust
Pyrethrins - Monterey Bug Buster-O; Fertilome Quik-Kill Home, Garden & Pet Spray
Spinosad - Fertilome Borer, Bagworm, Leafminer & Tent Caterpillar Spray; Bonide Captain Jack’s Dead Bug Brew; Bonide Colorado Potato Beetle Beater
 
To see the complete study, go to http://entomology.osu.edu/welty/pdf/VegIPMReport2005.pdf (Ward Upham)
 
Contributors:  Ward Upham, Extension Associate

If you plan on using a grub preventative on your lawn, the first half of July is a good target date for most products. Preventatives are normally used on areas that have had a history of grub problems.
 
Traditional grub insecticides such as Dylox or carbaryl (Sevin) are normally applied in late July after grubs are present or as a rescue treatment once damage is seen. Products that contain Merit (imidacloprid) are considered grub preventers.  Actually, these products do not prevent grubs, but rather kill grubs when they are quite small, and long before they cause damage. Merit is safer to use around pets and humans than traditional grub killers. Merit can be found in Bayer's Season-Long Grub Control, Grub No-More and Grub Free Zone.
 
Another grub preventer with the trade name GrubEx contains chlorantraniliprole. Though this product is very effective, it is less water soluble than imidacloprid. It should be applied earlier, preferably April or May, but applications through June should still be effective. Remember, all grub products should be watered in soon after application. (Ward Upham)

This time of year, two common leaf-spot diseases appear on tomato plants. Septoria leaf spot and early blight are both characterized by brown spots on the leaves.

Septoria leaf spot usually appears earlier in the season than early blight and produces small dark spots. Spots made by early blight are much larger and often have a distorted “target” pattern of concentric circles. Heavily infected leaves eventually turn yellow and drop. Older leaves are more susceptible than younger ones, so these diseases often start at the bottom of the plant and work up.
 
Mulching, caging, or staking keeps plants off the ground, making them less vulnerable. Better air circulation allows foliage to dry quicker than in plants allowed to sprawl. Mulching also helps prevent water from splashing and carrying disease spores to the plant.
 
In situations where these diseases have been a problem in the past, rotation is a good strategy. It is too late for that now, but keep it in mind for next year. Actually, rotation is a good idea even if you have not had problems in the past. But many gardens are too small to make it practical. If you have room, rotate the location of the tomatoes each year to an area that has not had tomatoes or related crops (peppers, potatoes, eggplant) for several years.
 
If rotation is not feasible, fungicides are often helpful. Be sure to cover both upper and lower leaf surfaces, and reapply fungicide if rainfall removes it. Plants usually become susceptible when the tomato fruit is about the size of a walnut. Chlorothalonil is a good choice for fruiting plants because it has a 0-day waiting period, meaning that fruit can be harvested once the spray is dry. Chlorothalonil can be found in numerous products including Fertilome Broad-Spectrum Landscape and Garden Fungicide, Ortho Garden Disease Control, GardenTech Daconil and others. Be sure to start protecting plants when the disease is first seen. It is virtually impossible to control this disease on heavily infected plants.
 
If chlorothalonil doesn’t seem to be effective, try mancozeb (Bonide Mancozeb Flowable). Note that there is a five-day waiting period between application and when the fruit can be harvested. You may wish to pick some tomatoes green just before you spray if you use Mancozeb as the tomato fruit will ripen inside. (Ward Upham)

Squash bugs are the grey, shield-shaped bugs that feed on squash and pumpkin plants. If you have had problems with these insects in the past, you know that they are almost impossible to control when mature. This is because the squash bugs have a hard body that an insecticide has difficulty penetrating. Thus, spraying when the insects are small is important. We are now seeing the nymphs of the first generation. These nymphs will eventually become adults, which will lay eggs that will become the second generation. The second generation is often huge and devastating. Therefore, it is important to control as many squash bugs now as possible.

Because squash bugs feed by sucking juice from the plant, only insecticides that directly contact the insect will work. General use insecticides such as permethrin (Bug-B-Gon Multi-Purpose Garden Dust, Green Thumb Multipurpose Garden and Pet Dust, Bug-No-More Yard and Garden Insect Spray, Eight Vegetable, Fruit and Flower Concentrate, Garden, Pet and Livestock Insect Control, Lawn & Garden Insect Killer), malathion, and methoxychlor provide control if a direct application is made to young, soft-bodied squash bugs. This means that you MUST spray or dust the underside of the leaves because this is where the insects live. (Ward Upham)

Euonymus scales look like small white cottony spots on affected euonymus foliage.  Leaves eventually turn yellow and die as feeding continues. Males are white and elongated, and  females are brown and oval shaped and about 1/16 inch long. Large numbers congregate on the undersides of leaves, twigs, and stems. About 60 days are required to complete a generation. In Kansas, there are two generations per year.
 
The first generation occurs in the spring. Overwintering females lay eggs that hatch in late May or early June. This period usually occurs when fringetrees, (Chionanthus), cockspur hawthorn (Crataequs crusgalli), Beautybush (Kolkwitzia amabilis) and Late Lilac (Syringa villosa) are in bloom.  Crawlers move to leaves and stem and begin to feed by sucking plant juices. Maturing males prefer leaves and females congregate on stems.
 
We are too late for control of crawlers for the first generation as this spray should coincide with early bloom of catalpa.  Full bloom of catalpa was on May 20 in the Manhattan area this year.
 
The second generation normally appears in late August to early September. Check to be sure crawlers are present before treating. Use a magnifying lens to identify the very small crawlers. If nothing is moving, crawlers are not active yet.
 
Labeled insecticides include malathion and acephate (Hi-Yield Acephate or Ortho Systemic Insect Killer),  permethrin (Hi-Yield 38 Plus Turf Termite and Ornamental Insect Control, Hi-Yield Indoor/Outdoor Broad Use Insecticide and Lawn & Garden Insect Killer, Fertilome Indoor\Outdoor Multi-Purpose Insect Spray) or cyhalothrin (Spectracide Triazicide, Bonide Caterpillar Killer).
 
Control is probably impossible for euonymus that has been heavily attacked and is in very poor health. Therefore, complete removal and destruction of the infested plants (including roots) is suggested. (Ward Upham)

Japanese beetles feed on over 300 species of plants including rose, birch, linden, crabapple, grape, Virginia creeper, and buckeye. Adults are approximately 7/16-inch long and metallic green with coppery wing covers. They sport a series of white dots made up of tufts of hair that project from under the edges of the wing covers on the back half of the insect. This characteristic is used to distinguish Japanese beetles from other similar beetles. Japanese beetles feed on leaves, flowers and wounded or mushy fruit. Adults often feed on the green material on the upper surface of the leaf leaving a lacelike or “cellophane” appearance. Most feeding activity occurs over a 4 to 6 week period though individual beetles usually live about 30 to 45 days.
 
Japanese beetles tend to be gregarious and feed in groups, starting at the top of a plant and working down. Warm, sunny weather is preferred with beetles favoring plants in full sun.  When disturbed, adults fold their legs and drop from foliage.  Adult beetles can be killed by shaking the beetles from the plant into a jar or bucket containing soapy water. This is best done in the morning when the insects are sluggish.
 
Numerous insecticides can be used including pyrethroid products such as cyfluthrin (Tempo, Bayer Vegetable & Garden Insect Spray), bifenthrin (Hi-Yield Bug Blaster II) and cyhalothrin (Bonide Beetle Killer, Spectracide Bug Stop Indoor + Outdoor Insect Killer, Spectracide Triazicide, Bonide Caterpillar Killer). Carbaryl (Sevin) can also be used. The pyrethroid products normally give 2 to 3 weeks protection with carbaryl not lasting as long; usually 1 to 2 weeks. All of the above insecticides are detrimental to natural controls such a parasitoids and predators or other pests including the two-spotted spider mite. Neem products (Natural Guard Neem-Py, Fertilome Triple Action Plus) and Pyola (pyrethrins in canola oil) will provide deterrence for 3 to 4 days. Japanese beetle traps tend to attract more beetles than they kill and often do more harm than good and therefore are not recommended. (Ward Upham)

Leaf scorch is starting to show up primarily on maples around the state. This is not a disease but rather a physiological problem associated with damaged roots, storm damage, limited soil area, or hot, dry winds. This year, the wet spring may have compromised root systems so that they are now struggling to provide the moisture needed by the leaves.  Moisture is lost so quickly from the leaves that roots can't absorb and transfer water quickly enough to replace what is lost. Though scorch is usually associated with droughty periods, it can appear even when the soil is moist.
 
Scorched leaves turn brown or, in some cases, turn black from the edges and between the major veins. If severe, the leaf may drop. Leaves may be affected over the entire tree or may be affected only on one side. White pines are also prone to this condition due to the delicacy of the needles.
 
Though scorch can be due solely to the weather, the condition of the roots of plants can make them much more susceptible to this condition. Shallow soils such as those over hardpan or rock lead to a limited root system that may not be able to absorb all the water needed. Trees may be more sensitive to scorch this year because of the heavy rains many areas received this spring.  In many cases so much rain was received that oxygen was driven from the soil resulting in root damage. That root damage is now making it more difficult for trees to provide all the water needed for the leaves. Also, root damage due to disease, insects, poor drainage or construction can cause poor water uptake.
 
To help alleviate damage due to dry soils or limited root systems, water once per week for recently transplanted trees of every two weeks for large trees if there is no rainfall. Mulching small trees or shrubs will help conserve moisture. (Ward Upham)

We mentioned in an accompanying article about using a soaker hose to water trees. We thought it might be helpful to provide more details.
 
Soaker hoses are notorious for non-uniform watering. In other words, you often receive too much water from one part of the hose and not enough from another. Hooking both the beginning and the end of the soaker hose to a Y-adapter helps equalize the pressure and therefore provide a more uniform watering. The specific parts you need are shown in the photo above and include the soaker hose, Y-adapter and female to female connector.

It is also helpful if the Y-adapter has shut off valves so the volume of flow can be controlled. Too high a flow rate can allow water to run off rather than soak in.
​
On larger trees, the soaker hose can circle the trunk at a distance within the dripline of the tree but at least ½ the distance to the dripline. The dripline of the tree is outermost reach of the branches. On smaller trees, you may circle the tree several times so that only soil which has tree roots will be watered. (Ward Upham)

Many areas of Kansas went through an extremely wet spring. Gardeners may assume that little watering may be needed this summer as the soils were completely recharged. However, many will likely need to do more watering than they expect.
 
Rain saturated soils can damage root systems.  Excess water drives oxygen out of the soil as pore spaces are filled with water. Every living cell in a plant must have oxygen to live. If there is no oxygen, roots will die.

Therefore, many of our plants may need to be babied through the summer, especially since it has turned so hot so quickly.
 
Newly planted trees are especially vulnerable as they have not established the extensive root system needed to absorb enough water during hot, dry, windy summers. Even trees two or three years old should receive special care even if the root system was not damaged by saturated soils.
 
Deep, infrequent watering and mulching can help trees become established. Newly transplanted trees need at least 10 gallons of water per week, and on sandy soils they will need that much applied twice a week. The secret is getting that water to soak deeply into the soil, so it evaporates more slowly and is available to the tree’s roots longer. One way to do this is to drill a small hole (1/8") in the side and near the bottom of a 5-gallon bucket and fill it with water. Let the water dribble out slowly next to the tree. Refill the bucket once, and you have applied 10 gallons. Very large transplanted trees and trees that were transplanted two to three years ago will require more water.
 
A perforated soaker hose is a great way to water larger trees, a newly established bed or a foundation planting. See the accompanying article for an inexpensive way to water trees.
 
In sunbaked soil, you may need to rough up the surface with a hoe or tiller to get water to infiltrate easily. It may be helpful to set the kitchen oven timer, so you remember to move the hose or shut off the faucet. If you are seeing surface runoff, reduce the flow.
 
Regardless of method used, soil should be wet at least 12 inches deep. Use a metal rod, wooden dowel, electric fence post or something similar to check depth. Dry soil is much harder to push through than wet. Record the time that was required to reach 12 inches and then use a time clock for any future waterings. (Ward Upham)
 
Contributors:  Ward Upham, Extension Associate

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)

Well, that is a question, but probably not the question most of you are thinking about. You may have considered stopping to dig up a plant that caught your eye on the side of the road at one time or another. I, myself, may or may not have participated in one such (ahem)…activity at some point in my life. But is it wise? Well, let’s talk about that for a minute.

First of all, moving a plant from its native place at the height of its season of interest is most often a fatal move. If the season of interest is anytime other than winter (when plants are dormant) then it is likely when the plant is actively growing. You probably notice plants on the side of the road most often when they are in bloom, which takes a great amount of energy (it is reproductive activity, after all). If the plant is actively growing and flowering, then it needs access to as many resources as it can get—all of the roots to gather water, nutrients and leaves to photosynthesize and make food.  Cutting off one of those resources (primarily roots when you dig it up) puts the plant under great stress. It needs a lot of water. If you plant it immediately, it MIGHT survive. It is unlikely to thrive right away if it does survive. More often, the process will kill the plant and your efforts will have been for naught. How disappointing.

There’s a bigger problem with ditch digging that has nothing to do with plant survival. Quite the opposite actually. Ever heard of kudzu, “The Plant That Ate the South?” Kudzu is a climbing vine that traverses anything in its path, including other trees and shrubs, which it shades out and kills. It was first introduced to the U.S. as an ornamental shrub, “an effortless and efficient shade producer” in 1876. Later (in the 30s and 40s), it was rebranded as a remedy for soil erosion and farmers were paid $8 an hour to sow it into more than one million acres of topsoil. Oh my.

Not all invasive species are introduced like kudzu was, but most are as challenging to get rid of as kudzu continues to be. What are invasive plants? These are nonnative, introduced species which have a tendency to spread and are believed to cause damage to the environment, the economy and/or human health. Please note the entire definition —tendency to spread and cause damage. We have a great many introduced ornamental plant species that grow and perform exceptionally well in our climate without also becoming invasive. Indeed, if it were not for plant hunters exploring the world, we would not have nearly the amount of diversity in our landscapes as we do today. Nor is a native-only landscape the only way to garden. It is a way to garden. Introduced species are not necessarily evil. But I digress, perhaps that is a discussion for another article.

The key here is to know what is considered invasive in our part of the world. This information can generally be found by searching for your state name and “invasive species.” The USDA manages lists from a national level and there are often statewide “council” organizations that provide educational material for free. For instance, the Kansas Forest Service (www.kansasforests.org) and the Kansas Native Plant Society (www.kansasnativeplantsociety.org) publish lists of plants considered the worst invasive species in the state. A highlight from this list is Amur honeysuckle (Lonicera maackii), which is quite eye catching both the spring (yellow/white flowers) and in the fall with its abundant bright red berries. But don’t move it to your house.  Wisdom, environ-mental concern and the law should prevail in this situation. It is against federal and state laws to grow or move (intentionally or unintentionally) species considered invasive (www.invasivespeciesinfo.gov/laws/publiclaws.shtml). I can’t calculate the likelihood of “plant police” pursuing you, but now you know better and can do your part to preserve our native lands.

It’s worth noting that not every plant is invasive in every state. For example, butterflybush (Buddleja) is a beautiful, free-flowering woody perennial that is available in just about any size and color you desire. They are excellent choices in the Great Plains. However, in Oregon they are considered invasive and are illegal for nurseries to grow and sell. Traditional species, that is. Because of their free-flowering (and free-seeding), many breeders have worked to develop sterile cultivars (producing 2% or less of viable seed) that can be grown and sold in regions where butterflybush is considered invasive. We benefit from these innovations with new colors, sizes and growth habits. Recent introductions you might be familiar with include the dwarf varieties Low and Behold® ‘Blue Chip’, ‘Blue Chip Jr.’, ‘Ice Chip’, ‘Lilac Chip’ and ‘Pink Micro Chip’. There are also some delicious-sounding cultivars in the Fluttterby Grandé™ series: ‘Blubberry Cobbler Nectar Bush’, ‘Peach Cobbler Nectar Bush’, ‘Sweet Marmalade Nectar Bush’, ‘Tangerine Dream Nectar Bush’ and ‘Vanilla Nectar Bush’. Boy, those marketers sure do know how to make our mouths water for new plants. Since we’re not in Oregon, you don’t need to know the full list of approved butterflybush cultivars. However, the invasive plant discussion is a passionate and nuanced one, which involves many puzzle pieces. In the end, it’s most important to “Know Before You Grow.” And that, my friends, is all anyone can ask.  (Cheryl Boyer)

These small, hopping insects are causing concern among gardeners because they are so noticeable. What people often see first is not the insect but the filaments of white, wool-like wax they leave behind. Nymphs are also coated with this white, powdery wax but adults of the species I've observed (citrus planthopper?) are more of a grayish color with a darker rear end. Only the adults have wings that are held over the body like a pup tent. Nymphs are more flattened and may not appear to be insects at first because of the waxy coating.

Plant injury due to these insects is usually minor. Feeding by large populations may cause death of seedlings or wilting of small twigs of larger plants. Control is usually not recommended because natural enemies often keep flatid planthoppers in check. If control is warranted, a strong stream of water from a hose should knock them off or a number of insecticides may be used including malathion, permethrin, cyfluthrin, and bifenthrin. For a detailed description, check out the University of Georgia Bugwood page at http://wiki.bugwood.org/Archive:Ash/Flatid_Planthoppers   (Ward Upham)

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)

There was a study done in 2005 by Ohio State University that compared the effectiveness of various biorational and natural products to more traditional pesticides. Squash bug was one of the insects that was a target organism. What was interesting is that certain products were more effective at different life stages. The researchers compared the effectiveness of products on young nymphs, old nymphs and adults. Following are the results for squash bug:

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)

Robin Ruether has been awarded the “Top 40 under 40” award from Greenhouse Product News Magazine. Robin manages the Prairie Star and Prairie Bloom Trials for Kansas State University. See http://www.prairiestarflowers.com/  She also authors a blog on flower varieties tested by KSU (http://www.prairiestarflowersblog.com/blog ), serves as an All-America Selections judge and contributes to the National Plant Trials Database.  Congratulations to Robin on a job well-done!  Link to original article:  http://www.gpnmag.com/robin-ruether.  (Ward Upham)

Contributors: Cheryl Boyer, Nursery Crops Specialist; Ward Upham, Extension Associate

This bacterial disease is a common disease in Kansas but rarely causes extensive losses in fruit quality or production. The disease affects leaves, fruit, and occasionally twigs. Leaf infections first appear as small, pale green to yellow angular spots. These spots normally are more prevalent near the leaf tip and are surrounded by a yellow halo. Eventually, the lesions turn dark brown, separate from healthy tissue, and drop out, giving the leaf a shot- hole appearance. On susceptible cultivars, 1 or 2 leaf lesions can cause a complete yellowing of the leaf and result in premature defoliation. 

Fruit infections are mostly superficial but more serious infections can cause pitting and cracking of the fruit surface.

Peach cultivars vary in their susceptibility to bacterial spot, although no variety is immune. Those cultivars showing tolerance to the disease include Belle of Georgia, Biscoe, Candor, Comanche, Dixired, Earliglo, Early-Free Red, Emery, Encore, Garnet Beauty, Harbelle, Harbinger, Harbrite, Harken, Late Sunhaven, Loring, Madison, Norman, Ranger, Redhaven, Redkist, Redskin, Sentinel, and Sunhaven.

Cultivars most susceptible to bacterial spot are Autumnglo, Autumn Lady, Blake, Elberta, Halehaven, July Elberta, Jersey Queen, Jerseyland, Kalhaven, Suncling, Suncrest, Sunhigh, Ran Cocas, Redcrest, Rio-Oso-Gem, and Sweet Sue. Most apricot and nectarine cultivars are susceptible to bacterial spot.

Excessive fertilization can predispose peaches to severe bacterial spot infections. On the other hand, proper fertilization is necessary to maintain tree vigor and to prevent the development of Cytospora canker. Monitoring the fertility needs of trees is best accomplished through soil and leaf analysis.

Since this disease is cause by a bacteria, fungicides found in fruit tree sprays are ineffective.  (Ward Upham)

This time of year, two common leaf-spot diseases appear on tomato plants. Septoria leaf spot and early blight are both characterized by brown spots on the leaves.

Septoria leaf spot usually appears earlier in the season than early blight and produces small dark spots. Spots made by early blight are much larger and often have a distorted “target” pattern of concentric circles. Heavily infected leaves eventually turn yellow and drop. Older leaves are more susceptible than younger ones, so these diseases often start at the bottom of the plant and work up.

Mulching, caging, or staking keeps plants off the ground, making them less vulnerable. Better air circulation allows foliage to dry quicker than in plants allowed to sprawl. Mulching also helps prevent water from splashing and carrying disease spores to the plant.  

In situations where these diseases have been a problem in the past, rotation is a good strategy. It is too late for that now, but keep it in mind for next year. Actually, rotation is a good idea even if you have not had problems in the past. But many gardens are too small to make it practical. If you have room, rotate the location of the tomatoes each year to an area that has not had tomatoes or related crops (peppers, potatoes, eggplant) for several years.

If rotation is not feasible, fungicides are often helpful. Be sure to cover both upper and lower leaf surfaces, and reapply fungicide if rainfall removes it. Plants usually become susceptible when the tomato fruit is about the size of a walnut. Chlorothalonil is a good choice for fruiting plants because it has a 0-day waiting period, meaning that fruit can be harvested once the spray is dry.  Chlorothalonil can be found in numerous products including Fertilome Broad-Spectrum Landscape and Garden Fungicide, Ortho Garden Disease Control, GardenTech Daconil and others. Be sure to start protecting plants when the disease is first seen. It is virtually impossible to control this disease on heavily infected plants.

If chlorothalonil doesn’t seem to be effective, try mancozeb (Bonide Mancozeb Flowable). Note that there is a five-day waiting period between application and when the fruit can be harvested. You may wish to pick some tomatoes green just before you spray if you use Mancozeb as the tomato fruit will ripen inside. (Ward Upham)

Under favorable weather conditions, potatoes produce fruit. These structures are borne on the top of the plant and look much like small tomatoes. (Tomatoes and potatoes are closely related). Potato fruits are not edible. They contain a toxic substance (solanine) that can cause illness if eaten. Also, potato fruits should not be saved for seed because progeny does not come true. Rather, remove and dispose of fruit so children do not eat them. (Ward Upham)

Rose rosette is a serious problem in Kansas on wild roses (Rosa multiflora) in pastures and hedges. It is also found in domestic rose plantings.

Infection is thought to start with rapid elongation of a new shoot. The rapid shoot growth may continue for several weeks to a length of two to three feet. Following shoot elongation, a witches' broom or clustering of small branches occurs. The stems develop excessive thorniness and produce small, deformed leaves with a reddish-purple pigmentation. Stems and petioles of Rosa multiflora plants may have reddish blotches or streaks. Rose plants infected with the rose rosette virus die rapidly, usually within one to two years.

Rose rosette is caused by an aster yellows phytoplasma.  Transmission of the disease has been shown experimentally through grafting and through an eriophyid mite, Phyllocoptes frutiphilus. Though KnockOut roses are resistant to many diseases, they are susceptible to this one.

There is no effective control measure for infected plants. In garden settings, infected plants should be removed and destroyed, including roots. Any roots that remain after plant removal may produce infected shoots which can harbor the disease.

If possible, eliminate all multiflora rose plants from the vicinity as they are extremely susceptible and will act as a carrier. Multiflora rose is the wild rose often seen growing in ditches and pastures.

Since the disease can be transmitted by pruning shears, disinfect the shears when moving from one plant to another by using rubbing alcohol or a disinfectant such as Lysol. (Ward Upham)

The first defense against borers is to maintain healthy, vigorous growth on peach trees. Do a good job of pruning, keep trees watered as needed, and control peach leaf curl (see http://www.hfrr.ksu.edu/doc3168.ashx ). Young trees are more likely to be attacked than older ones if the older trees are healthy.

Sprays should be applied the last week in June and again the last week in July for good control. Thoroughly cover the bottom portion of the trunk to the point that some spray pools at the base of the tree. Peach tree borers lay eggs on the tree trunk. When the larva hatches, it tunnels through the bark into the tree. If an insecticide is present on the trunk, the larva is killed when it tries to tunnel.     

Most of the active ingredients that were labeled for peach tree borer and lesser peach tree borer in homeowner packaging are now gone, except for permethrin, which is found in numerous products.  Those that have peach tree borer on the label include Hi-Yield Garden, Pet and Livestock Insect Control, Hi-Yield 38, Bonide Borer-Miner Killer and Gordon’s Bug-No-More Yard and Garden Insect Spray. (Ward Upham)

Squash bugs are the grey, shield-shaped bugs that feed on squash and pumpkin plants. If you have had problems with these insects in the past, you know that they are almost impossible to control when mature. This is because the squash bugs have a hard body that an insecticide has difficulty penetrating. Thus, spraying when the insects are small is important. We are now seeing the nymphs of the first generation. These nymphs will eventually become adults, which will lay eggs that will become the second generation. The second generation is often huge and devastating. Therefore, it is important to control as many squash bugs now as possible.

Because squash bugs feed by sucking juice from the plant, only insecticides that directly contact the insect will work. General use insecticides such as permethrin (Bug-B-Gon Multi-Purpose Garden Dust, Green Thumb Multipurpose Garden and Pet Dust, Bug-No-More Yard and Garden Insect Spray, Eight Vegetable, Fruit and Flower Concentrate, Garden, Pet and Livestock Insect Control, Lawn & Garden Insect Killer), malathion, and methoxychlor provide control if a direct application is made to young, soft-bodied squash bugs. This means that you MUST spray or dust the underside of the leaves because this is where the insects live. (Ward Upham)

We have had reports of this pest in Wichita and the Manhattan area. Though this weevil does feed on other elms including American and Chinese elms, Siberian elm is preferred.

The adult of this insect is a very small (1/8 inch) brown weevil with dark spots on the back. It sports a short, curved snout and has the ability to hop.

Eggs from overwintering adults hatch on newly formed leaves. The larva produces a serpentine pattern in the leaf that terminates on a leaf edge.  Adults have emerged now and are feeding on the leaves. Adult feeding damage produces a shothole pattern in the leaves. Heavily fed upon leaves appear lacy. There is one generation per year and so when the adults disappear, there should be no further damage this year.

I have not seen any control strategies for this insect. Trees typically recover from spring defoliations. (Ward Upham)

Contributors: Ward Upham, Extension Associate

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)

Though we normally see this condition most commonly on tomatoes as evidenced by a sunken,brown, leathery patch on the bottom of the fruit,this year we are also seeing it on summer squash. Not a disease, this condition is caused by a lack of calcium in the developing fruit. It is often assumed that this means there is a corresponding lack of calcium in the soil. This is not necessarily the case, especially in Kansas. Most Kansas soils have sufficient levels of calcium. So what causes blossom-end rot? Actually, there are a number of possible causes. Let's look at some of them.

- This year, inconsistent amounts of water may be a factor for our squash. This can be due to watering practices or may be due to heavy rains followed by dry periods. Try to keep soil moist but not waterlogged. Mulching can help by moderating moisture levels over time.

- Vegetable tops will sometimes outgrow the root system during cooler spring weather. This is especially true of tomatoes. As long as it is cool, the root system can keep up. When it turns hot and dry, the plant has a problem, and water —with the calcium it carries — goes to the leaves and the fruit is bypassed. The plant responds with new root growth and the condition corrects itself after a couple of weeks.

- Heavy fertilization, especially with ammonium forms of nitrogen, can encourage this condition. Heavy fertilization encourages more top than root growth and the ammonium form of nitrogen competes with calcium for uptake.

- Anything that disturbs roots such as hoeing too deeply can encourage blossom-end rot. Mulching helps because it keeps the soil surface cooler and therefore a better environment for root growth.

There are some years you do everything right and the condition still shows up due to the weather. In such cases, remember that blossom-end rot is a temporary condition, and plants should come out of it in a couple of weeks. You may want to pick off affected fruit to encourage new fruit formation.

Soils with adequate calcium will not benefit from adding additional calcium. If your soil is deficient in this nutrient, add 1 pound gypsum per 100 square feet. Gypsum is calcium sulfate and will not affect pH. Though calcium raises pH, sulfate lowers it and the two cancel each other out. Even if not needed, gypsum will not hurt anything.

We have also found that spraying plants with calcium doesn't work. The fruit's waxy surface doesn't allow absorption of the material and calcium does not move from the leaves to the fruit. (Ward Upham)

Trees naturally shed bark as they grow. The amount of bark shed varies significantly from one year to the next and is usually not noticeable. But some trees, such as sycamore, London Planetree and silver maple, shed bark in large patches or strips. During a year with heavy shedding homeowners may become concerned that the tree is sick or dying. Such usually is not the case. Sycamore and London Planetree normally show a bright green color on the branches when the bark first falls off but soon return to normal. Maple reveals an orange color after shedding but it, too, soon returns to normal. Eastern redbud tends to shed bark on older trees revealing an orangish-brown inner bark. There is nothing wrong with the tree as long as the shedding bark simply reveals underlying bark rather than bare wood. (Ward Upham)

If you notice leaves disappearing from walnut trees, it may be walnut caterpillars. Walnut caterpillars attack primarily black walnut, pecan, and several species of hickory trees, but may also attack birch, oak, willow, honey locust, and apple trees.

Walnut caterpillars overwinter as pupae underground beneath host trees. In late spring, moths emerge and deposit egg clusters on lower leaves. By the end of June, newly emerged and gregarious larvae skeletonize leaves. Larger hairy,brick-red larvae consume greater amounts of leaf tissue, and nearly matured gray larvae devour entire leaves, including petioles.

As mentioned earlier, walnut caterpillars are gregarious. In other words, they feed in groups. A single tree may contain several groups. When disturbed, larvae arch their bodies in what looks like a defensive move. Larvae crowd together on the lower parts of trees to molt and leave an ugly patch of hairy skins. Mature larvae, 2 inches long, descend or drop to the ground where they enter the soil to pupate. A second generation occurs soon, creating the overwintering pupae.

Removing leaves with egg masses is an effective way to control walnut caterpillars. This may be impractical with large trees or when too many infested leaves are present. Bands of Tree Tanglefoot pest barrier may be used to snare larvae as they migrate to main branches or the trunk to molt. Insecticides such as spinosad (Conserve; Captain Jack’s Dead Bug Brew; Borer, Bagworm, Leafminer and Tent Caterpillar Spray) permethrin (numerous trade names) malathionor cyfluthrin (Tempo, Bayer Vegetable and Garden Insect Spray) may provide the most practical means of control. (Ward Upham)

These small, hopping insects are causing concern among gardeners because they are so noticeable.What people often see first is not the insect but the filaments of white, wool-like wax they leave behind. Nymphs are also coated with this white, powdery wax but adults of the species I've observed (citrus planthopper?) are more of a grayish color with a darker rear end. Only the adults have wings that are held over the body like a pup tent. Nymphs are more flattened and may not appear to be insects at first because of the waxy coating.

Plant injury due to these insects is usually minor. Feeding by large populations may cause death of seedlings or wilting of small twigs of larger plants. Control is usually not recommended because natural enemies often keep flatid planthoppers in check. If control is warranted, a strong stream of water from a hose should knock them off or a number of insecticides may be used including malathion, permethrin, cyfluthrin, and bifenthrin. For a detailed description, check out the University of Georgia Bugwood page.(Ward Upham)

There was a study done in 2005 by Ohio State University that compared the effectiveness of various biorational and natural products to more traditional pesticides. Squash bug was one of the insects that was a target organism. What was interesting is that certain products were more effective at different life stages. The researchers compared the effectiveness of products on young nymphs, old nymphs and adults. Following are the results for squash bug:

To see the complete study, go to http://entomology.osu.edu/welty/pdf/VegIPMReport2005.pdf  (Ward Upham)

Contributors: Ward Upham, Extension Associate

This time of year, two common leaf-spot diseases appear on tomato plants. Septoria leaf spot and early blight are both characterized by brown spots on the leaves.

Septoria leaf spot usually appears earlier in the season than early blight and produces small dark spots. Spots made by early blight are much larger and often have a distorted “target” pattern of concentric circles. Heavily infected leaves eventually turn yellow and drop. Older leaves are more susceptible than younger ones, so these diseases often start at the bottom of the plant and work up.

Mulching, caging, or staking keeps plants off the ground, making them less vulnerable. Better air circulation allows foliage to dry quicker than in plants allowed to sprawl. Mulching also helps prevent water from splashing and carrying disease spores to the plant.  

In situations where these diseases have been a problem in the past, rotation is a good strategy. It is too late for that now, but keep it in mind for next year. Actually, rotation is a good idea even if you have not had problems in the past. But many gardens are too small to make it practical. If you have room, rotate the location of the tomatoes each year to an area that has not had tomatoes or related crops (peppers, potatoes, eggplant) for several years.

If rotation is not feasible, fungicides are often helpful. Be sure to cover both upper and lower leaf surfaces, and reapply fungicide if rainfall removes it. Plants usually become susceptible when the tomato fruit is about the size of a walnut. Chlorothalonil is a good choice for fruiting plants because it has a 0-day waiting period, meaning that fruit can be harvested once the spray is dry.  Chlorothalonil can be found in numerous products including Fertilome Broad-Spectrum Landscape and Garden Fungicide, Ortho Garden Disease Control, GardenTech Daconil and others. Be sure to start protecting plants when the disease is first seen. It is virtually impossible to stop it on heavily infected plants.

If chlorothalonil doesn’t seem to be effective, try mancozeb (Bonide Mancozeb Flowable). Note that there is a five-day waiting period between application and when the fruit can be harvested. You may wish to pick some tomatoes green just before you spray if you use Mancozeb as they will ripen inside. (Ward Upham)

This is the time of year that onions grow and develop rapidly. Regular watering (if needed) and a light fertilization are helpful to maximize growth. Onions develop so that as much as 2/3 of the bulb remains out of the soil. This is normal and there is no need to cover the bulb with soil.

A gardener can tell when onions are nearing harvest time by some of the tops falling over. You may wish to break over the tops that haven’t fallen to encourage drying of the neck. Allow a few days to pass and then dig the onions to insure they don’t sunburn. Temporarily store them in a dry, well-ventilated area for a week or two before cutting the tops to insure the necks are completely dry. Remove the foliage (or braid the leaves) and store in a cool, dry location. (Ward Upham)

Rose rosette is a serious problem in Kansas on wild roses (Rosa multiflora) in pastures and hedges. It has also occasionally been found in domestic rose plantings.

Infection is thought to start with rapid elongation of a new shoot. The rapid shoot growth may continue for several weeks to a length of two to three feet. Following shoot elongation, a witches' broom or clustering of small branches occurs. The stems develop excessive thorniness and produce small, deformed leaves with a reddish-purple pigmentation. Stems and petioles of Rosa multiflora plants may have reddish blotches or streaks. Rose plants infected with the rose rosette virus die rapidly, usually within one to two years.    

Rose rosette is caused by an Emaravirus species.  Transmission of the disease has been shown experimentally through grafting and is also thought to be spread by mites. Though KnockOut roses are resistant to many diseases, they are susceptible to this one.

There is no effective control measure for infected plants. In garden settings, infected plants should be removed and destroyed, including roots. Any roots that remain after plant removal may produce infected shoots which can harbor the disease.

If possible, eliminate all multiflora rose plants from the vicinity as they are extremely susceptible and will act as a carrier. Multiflora rose is the wild rose often seen growing in ditches and pastures. Since the disease can be transmitted by pruning shears, disinfect the shears when moving from one plant to another by using rubbing alcohol or a disinfectant such as Lysol. (Ward Upham)

Every year we see damage caused by exposure to herbicides. Symptoms vary with herbicide applied, plants exposed, concentration of product and environmental factors. Here is a list of the types of damage commonly seen.

Broadleaf herbicide drift. A number of herbicides used on farms and on home lawns are essentially plant growth hormones. These include 2,4-D, triclopyr, and dicamba and are commonly used to control broadleaf weeds in lawns, pastures, or grassy crops. These products may become a gas (volatilize) at high temperatures, causing them to drift and damage nontarget plants such as trees and shrubs. Symptoms may include twisting and distortion of plant foliage, leaf yellowing, and, in severe cases, branch dieback. One of the trademark signs of this damage is the curly-Q twisting of leaf petioles or stems. Though tomatoes, redbud trees, and grapes are sensitive to these herbicides, a number of species will show some damage if drift has occurred. If you see twisting on more than one species, chances are that herbicide drift has occurred. Often, plants recover from drift due to volatilization.

Damage to vegetable gardens. Though drift is the most common cause of herbicide damage on vegetables, other potential problems exist as well. Cattle fed prairie hay from pasture treated with picloram (Tordon) can have manure tainted with the herbicide. If this manure is used on a vegetable garden, plants may sicken and die. Also, lawn clippings treated with quinclorac (a crabgrass killer) and used as mulch can have the same effect. Both products can remain active for up to 24 months.

Damage from stump or sprout treatments. Tree stumps often are treated to prevent resprouting. Two commonly used products are picloram (Tordon) and triclopyr (Remedy, Stump Killer, Brush-B-Gon, etc.). Be careful when applying these herbicides to prevent contamination of the soil. Nearby trees may be damaged if they pick up enough herbicide. Foresters warn that picloram also may leach from roots of a treated tree into the soil and be absorbed by roots of another tree species. This does not occur with triclopyr. Be very careful about using these products near valuable trees and shrubs.

Sprouts are often treated to keep them from growing where they interfere with the aesthetics of a lawn or other landscaped area. Never use a herbicide to treat sprouts coming from a root system of a tree you want to keep. A number of tree species including honey locust, black locust, hackberry, western soapberry, persimmon, and occasionally, maples may send up sprouts from their roots.

Treating these sprouts will effectively treat the tree to which they are attached. This may ultimately kill the tree. Also remember that trees of the same species growing next to one another may share a root system as a result of root grafting. Treating one tree in the group is like treating all of the trees.

If treating volunteer sprouts, use a product such as Monterey Sucker-Stopper. It will not harm the plant to which the sprouts are attached.


Liquid Weed Edgers. Herbicides are often used along fences, on sidewalks or gravel drives to prevent plant growth. Some of these, including glyphosate (Roundup) and glufosinate (Finale) rarely causes damage unless sprayed directly on the foliage of a shrub or tree. Other liquid weed edger products are soil sterilants and have a long residual (months to years) in soil and are highly toxic to trees and shrubs. Symptoms may include yellowing, marginal leaf scorching, branch dieback and tree mortality. Once the tree takes up these products through their roots, they suffer permanent damage. Never use these soil sterilants in areas where tree roots may be exposed.  Remember that tree roots extend well beyond the drip line. It is almost impossible to use liquid weed edgers in the landscape without coming in contact with tree roots. Also remember that some of these products, such as prometon, will move with water until they become affixed to the soil. (Ward Upham)

Squash bugs are the grey, shield-shaped bugs that feed on squash and pumpkin plants. If you have had problems with these insects in the past, you know that they are almost impossible to control when mature. This is because the squash bugs have a hard body that an insecticide has difficulty penetrating. Thus, spraying when the insects are small is important. We are now seeing the nymphs of the first generation. These nymphs will eventually become adults, which will lay eggs that will become the second generation. The second generation is often huge and devastating. Therefore, it is important to control as many squash bugs now as possible.

Because squash bugs feed by sucking juice from the plant, only insecticides that directly contact the insect will work. General use insecticides such as permethrin (Bug-B-Gon Multi-Purpose Garden Dust, Green Thumb Multipurpose Garden and Pet Dust, Bug-No-More Yard and Garden Insect Spray, Eight Vegetable, Fruit and Flower Concentrate, Garden, Pet and Livestock Insect Control, Lawn & Garden Insect Killer), malathion, and methoxychlor provide control if a direct application is made to young, soft-bodied squash bugs. This means that you MUST spray or dust the underside of the leaves because this is where the insects live. (Ward Upham)

Daytime/midday butterfly flurries along trails invariability are attributed to hackberry caterpillar butterflies. Outbreaks of hackberry butterflies are sporadic and unpredictable. While hackberry butterflies are present every year and often go unnoticed, “outbreaks” may cause concern.

Exact reasons to explain outbreaks are unknown. An often-cited reason to explain them is the  mildness or severity of the previous winter. This breaks down, however, if one looks at a relatively limited geographical area experiencing a spate of hackberry butterflies, against other areas which experienced the same winter conditions ---- which begs the question, “Why here and not there?”

The definitive work done by C. V. Riley in Missouri )1874( documented that hackberry butterflies produced 2 generations per year, with the larvae emerging from the eggs of second generation moths being the overwintering form. Based on this, there would be little reason not to expect the same 2 generation scenario in Kansas.  So what is the commotion about regarding hackberry caterpillar butterflies? It is the butterfly themselves, as well as the impact of larval activities.

The presence of the larvae precedes that of the butterflies. The head of the larva has an interesting look: a black horned appearance.

In the absence of people, hackberry caterpillars go about their business without causing concern. However when people decide to “invade” the domain of hackberry caterpillars, a couple of situations occur. First, if picnicking beneath hackberry trees in which caterpillars are feeding, the rain-of-fecal pellets can be unappetizing.

Second, after caterpillars have completed their feeding up in the canopy of hackberry trees, they descend to the ground in search of a site in which they will pupate. This stream of caterpillars (again in the presence of people) may be disconcerting.

Tremendous numbers of larvae translate into eventual tremendous numbers of butterflies. Thus, the “nuisance factor” continues upon completion of pupation and the emergence of the “new” butterflies. (Bob Bauernfeind)

This is a new pest for me, but I have had two calls on elm flea weevil causing damage to Siberian elm in the last week.  One was from northern Kansas (Mitchell County) and the other further south in the Wichita area. Though this weevil does feed on other elms including American and Chinese elms, Siberian elm is preferred.

The adult of this insect is a very small (1/8 inch) brown weevil with dark spots on the back. It sports a short, curved snout and has the ability to hop.

Eggs from overwintering adults hatch on newly formed leaves.  The larva produces a serpentine pattern in the leaf that terminates on a leaf edge.  Adults have emerged now and are feeding on the leaves.  Adult feeding damage produces a shothole pattern in the leaves.  Heavily fed upon leaves appear lacy.  There is one generation per year and so when the adults disappear, there should be no further damage this year.

I have not seen any control strategies for this insect.  Trees typically recover from spring defoliations.  (Ward Upham)

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 fairy ring 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. Also, 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)   

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