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Blog Post: http://www.ksuhortnewsletter.org
Video of the Week: Butterfly Gardens
https://kansashealthyyards.org/all-videos/video/butterfly-gardens
REMINDERS
Apply preemergent herbicide to lawn if you haven’t already
Turn compost pile
Prune spring-flowering shrubs such as forsythia and lilac after blooming if needed
Sidedress cabbage, broccoli and cauliflower 3 weeks after transplanting. See https://tinyurl.com/j2ggaa6 for sidedressing chart.
Sidedress onions 2 to 4 weeks after transplanting.
FRUIT
Pest Control on Fruit Trees
It can be a challenge to know how to spray fruit trees for pest control. Spray schedules will vary depending on whether the trees have fruit or not. Following are hints on what to spray this year for our most common fruit trees.
Peaches, nectarines and apricots: Often late frosts prevent fruit set on these fruit. Trees that are in full bloom, become much more sensitive to frost damage than those with buds still closed. Temperatures at 28 degrees and lower will harm buds that are in full bloom.
If there will not be any fruit, there isn’t any need for being on a spray schedule. If there is fruit, use a product that contains captan or myclobutanil (Immunox, Fungi-Max, Fertilome F-Stop Lawn and Garden Spray) from now until about two weeks before harvest. Spray about every 10 days.
If a specific problem develops such as borers, peach leaf curl or gummosis on peach, see our listing of common problems at our “Common Plant Problems in Kansas” website. Look under “Peach” for possible problems and what to do about them.
Cherries: We often have good fruit on cherries without spraying. However, a wet period as fruit ripens can lead to problems with brown rot. Myclobutanil (Immunox, Fertilome F-Stop Lawn and Garden Spray, Fungi-Max) or Captan will give good protection. Cherry fruit fly may attack the cherries with the maggot causing damage to the fruit. Malathion (check label), Bonide Fruit Tree & Plant Guard or Sevin can be used for control.
Pears: Pears are often able to escape damage without spraying. If trouble does arise, use the same recommendations given for apples.
Apples: Apples are the crop most in need of a spray schedule. Unless you have disease-resistant trees, cedar-apple rust is a perennial problem. The larvae of the codling moth is the insect most likely to damage fruit. Control can be a challenge due to changing labels and an extended spray season. See our article in our March 22, 2022 newsletter on “Apple Tee Sprays” for details.
We have three publications that give an overview of fruit pest control that are helpful.
Spray Schedules for Growing Apples at Home
Spray Schedules for Growing Stone Fruit at Home
Fruit Pesticides, Active Ingredients, and Labeled Fruits
Don’t overlook the “Fruit Pesticides…” pub as it lists trade names as well as other very important information. (Ward Upham)
Fruit Tree Sprays and Rain
A spreader-sticker is used to improve the distribution and retention of fungicides and insecticides on fruit and leaves. Many gardeners may not be familiar with these products but they can help our fungicides and insecticides work better. Look for a product that is called “Spreader-Sticker.” Big box stores rarely carry these products but garden centers or well-stocked hardware stores often do. These products should be used with fruit tree sprays as it allows the spray to coat leaves and fruit more thoroughly and to resist being washed off during rain events. However, even with a spreader-sticker, a rain can reduce the length of time the materials are effective. Less than one inch of rain since the last spray will not significantly affect residues. As a general rule, one to two inches of rain will reduce the residue by one half. Reduce the number of days until the next spray by one half. More than two inches of rain since the last spray will remove most of the spray residue. Re-spray as soon as possible. These recommendations apply for a soft, gentle rain. If you have a hard, driving rain, cut the above recommendations in half. (Ward Upham)
Controlling Weeds in Strawberries
Strawberries are one of the most popular fruits, but gardeners often have problems with weed control. Strawberries form a mat of plants, which makes hoeing difficult. Gardeners must pull weeds by hand or use herbicides. In small plantings, hand weeding is usually sufficient as weeds become less of a problem when the plants canopy over to block sunlight to the soil. In larger plantings, herbicides may prove helpful.
Although there are no weed preventers available for homeowners to use on strawberries, Poast (sethoxydim), a grass-killing herbicide, can be used after weedy grasses have emerged. It can be sprayed directly over strawberries without harm but should not be applied within 7 days of harvest. You can find Poast in Fertilome Over the Top II, Hi-Yield Grass Killer and Monterey Grass Getter. (Ward Upham)
PESTS
Ash/Lilac Borer
Note: Ash/Lilac Borer is a different insect than Emerald Ash Borer. Ash/Lilac Borer has been around for many years while Emerald Ash Borer has been confirmed in only Atchison, Doniphan, Douglas, Jackson, Jefferson, Johnson, Leavenworth, Miami, Shawnee & Wyandotte counties in Kansas.
If you have had problems with canes or stems of lilac and privet suddenly wilting, or ash trees that show borer holes in the trunk and larger branches, the ash/lilac borer may be to blame. This insect causes the base of infested lilac stems to swell and the bark to separate from the wood. A fine sawdust-like material is present around holes in the canes. Ash and mountain ash also are affected. The borer attacks the trunk, which may cause bark to swell and crack if there are repeated infestations.
Ash/lilac borers overwinter as larvae in infested trees and shrubs. Moths generally begin to emerge in mid to late April. Emergence peaks in May, dwindles by mid to late June and ends by the first week of July. However, this varies by year. The moth has clear wings and resembles a wasp. There is one generation per year.
Public and commercially managed properties often use pheromone traps to determine the presence of adults. Spray treatments are started seven to 10 days after capture of the first moths.
Sprays also can be timed using phenology, the practice of timing one event by another. The first spray for ash/lilac borer should be applied when the Vanhoutte spirea is in full to late bloom. This is often about the third week in April but can be as early as late March and as late as mid-May. Apply a second spray four weeks after the first. The Missouri Botanical Garden has several images of Vanhoutte spirea.
Thoroughly treat the trunk and larger limbs of ash or the lower portion of the stems of lilac or privet. Heavily infested ash should be cut and burned during the fall and winter. Infested stems of lilac or privet should be removed as well.
Products with bifenthrin or permethrin (Hi-Yield Garden, Pet, and Livestock Insect Control and 38 Plus Turf, Termite and Ornamental Insect Control) are labeled for control. Though there are a number of homeowner products that contain one or the other of these two active ingredients, the permethrin products listed above are the only ones I’ve found that specifically lists the ash/lilac borer on the label with directions for control. (Ward Upham)
Mole Control
Though moles spend most of their time underground, the damage they cause above ground is all too visible. Meandering paths of upheaved soil are evidence of the small mammals foraging for food. If soil is dry, moles form mounds of soil but do not make the meandering paths. Some tunnels may be abandoned soon after being built while others are travel lanes and used for a longer period of time. Even though moles do not feed on plant matter, they can still cause damage by disturbing roots and uprooting small plants.
Numerous home remedies have been concocted to control moles including chewing gum, noisemakers, broken glass, bleaches, windmills, and human hair. None have been found to provide consistent and reliable control. Poison baits also fail to work because moles feed on earthworms and grubs, not vegetable matter. Even grub control products are ineffective as they do not control earthworms, and earthworms are the primary food source for moles.
The best control method is the use of traps. There are three types of traps (harpoon, choker, and scissor-jawed) and each can be effective but may take some time to master. Try the following suggestions.
Moles use some tunnels more than others. Use a broomstick or something similar to poke holes in a number of runs. Check a day later to see which runs have been “repaired.’ These are the active runs and should be used for trap placement.
Place a trap in an active run by excavating soil, placing the trap and then replacing loose soil. Secure the trap so that the recoil will not lift the trap out of the ground. Make sure the triggering mechanism is in the center of the run.
Finally, push down two more holes, one on each side of the trap. Moles should be caught when they try to repair the tunnel. Move traps if no moles are caught within three days.
Our KSU Extension Wildlife Management website has information on mole control including videos and printed material. (Ward Upham)
TURFGRASS
Controlling Wild Violets in Lawns
One of the most difficult weeds to control in lawns is the wild violet. Even combination products that contain 2,4-D, MCPP and Dicamba such as Trimec, Weed-Out and most formulations of Weed-B-Gon do not do a good job. Products with triclopyr give much better control though more than one treatment will likely be needed. The products that contain triclopyr on the homeowner side are Turflon Ester, Triclopyr Ester and Weed-B-Gon Chickweed, Clover & Oxalis. (Note: There are several formulations of Weed-B-Gon but only Weed-B-Gon Chickweed, Clover & Oxalis contains triclopyr.)
The products listed above are labeled for tall fescue and Kentucky bluegrass. Do not use products containing triclopyr on bermudagrass as severe injury will occur. Weed-B-Gon Chickweed Clover & Oxalis is labeled for buffalograss and zoysia (Turflon Ester and Triclopyr Ester are not) but lawns will likely show some temporary browning after application.
Spray only on calm days and when temperatures are below 90 degrees to avoid damage to nearby plants. (Ward Upham)
MISCELLANEOUS
Butterfly Gardening
Butterfly gardening is becoming more popular with Kansans. Providing for the basic needs of butterflies, such as food, shelter and liquids, will encourage butterflies to visit this summer. There are a number of plants that attract butterflies. However, different species of butterflies prefer different plants. Using a variety of plant material that vary in blooming times of day and year helps attract a diverse group of visitors. Plant groups of the same plant together; a single plant is difficult for a butterfly to detect. If trying to attract a certain species of butterfly, learn which plant(s) that butterfly prefers and then emphasize that plant in your planting. Annuals that attract butterflies include ageratum, cosmos, French marigold, petunia, verbena and zinnia.
Perennials and shrubs can be split into those that bloom early, mid-season and late. Good choices for those that bloom early are allium, chives, forget-me-not and lilac. Bee balm, butterfly bush, black-eyed Susan, buttonbush, butterfly weed, daisy, daylily, gaillardia, lavender, lily, mint, phlox, privet, sunflower and veronica are fitting picks for mid-season bloom. Late bloomers include aster, glossy abelia and sedum.
There are other things you can do to encourage butterflies. Butterflies are cold-blooded and like open areas where they can sun themselves on cool days and shade to cool off when the sun is too intense.
Butterflies also need water. A simple way to make a butterfly pool is to take a bucket, fill it with gravel, and bury it to the rim. Now add water, sugar water or sweet drinks so that the butterflies can land on the gravel but still reach the liquid.
Monarch Watch is an organization that focuses on Monarch butterflies and supplies free milkweed plants for relatively large restoration projects as well schools and educational non-profits. The site also provides extensive information on the Monarch butterfly and on what you can do to increase the population.
Our Johnson County Master Gardeners have put together a fact sheet on creating a butterfly habitat. (Ward Upham)
Clover Mites
Though clover mites are large by mite standards, they are still smaller than a pinhead. Because they are so small, they can easily invade homes through tiny openings around windows and doors. Though tiny, clover mites are very noticeable due to their reddish color. They are also easily identified by their long front legs, which are about twice as long as the other legs.
Clover mites do not bite people (they are plant feeders) or directly damage home furnishings but can leave unsightly stains on curtains, walls, carpets and other structures if they are crushed.
Mites can be removed from inside the home with a vacuum cleaner. Bags should be removed and sealed after use to prevent mites from escaping.
It can also be helpful to try to prevent clover mites from entering the home through the use of physical barriers and miticides. Mites do not readily cross loose, clean, cultivated soil, so a band about 18 to 24 inches wide all around the house, kept free of grass, will help deter potential invaders. Also, clover mites are so small that applying talcum powder, diatomaceous earth, corn starch or baking soda around entry points can stop clover mites by creating a barrier. Even double sticky tape placed on windowsills will catch the small mites when they try to pass. Replace the tape when it fills. Do not crush clover mites as they will leave a rusty stain.
Homeowners can also keep mites from entering the home by spraying the outside walls and border areas of the lawn and cultivated soil with effective miticides next to the foundation. Try to treat when daytime temperatures will be at least 60 degrees F because the effectiveness of
miticides is greatly reduced by cooler temperatures. Spray outside walls and foundations with
lambda cyhalothrin (Spectracide Triazicide, Scimitar) or bifenthrin (Hi Yield Bug Blaster
Bifenthrin, Hi Yield Bug Blaster II, Talstar). The house should be sprayed from the lower windowsill down to the ground. Pay particular attention to cracks and crevices in clapboards, shingles, foundation and around basement windows. Be sure to spray up and into the area between the bottom of the house siding and the foundation. (Ward Upham)
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Contributors: Ward Upham, Extension Associate
Division of Horticulture
1712 Claflin, 2021 Throckmorton
Manhattan, KS 66506
(785) 532-6173
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Cooperating, Ernie Minton, Dean.
