Horticulture 2025 Newsletter  No. 12

Manhattan, KS 66506     (785) 532-6173

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Home gardeners can contact their local Extension agency for support in all topics related to horticulture. Don’t know who your agent is? Visit: https://www.ksre.k-state.edu/about/statewide-locations/ to find out.

Agents please use the email address [email protected] to send in any questions with which you need assistance.

Eating locally grown produce, protein, grains and dairy supports farmers and the local economy. Fresh, seasonal, Kansas-grown food provides high quality nutrition to your diet. This beautifully illustrated poster shows which foods are in season throughout the year.

Download it free from the K-State bookstore online: https://bookstore.ksre.ksu.edu/download/kansas-seasonal-local-food-poster_MF3712

Rocky Ford Turfgrass Research Center in Manhattan

This Field Day program is designed for all segments of the turf & ornamentals industry — lawn care, athletic fields, golf courses, sod farms, landscape, nursery, and grounds maintenance.  Included on the program are research presentations, problem diagnosis, commercial exhibits, and equipment displays. There will be time to see current research, talk to the experts, and get the answers to your questions.

For more information and to register online, go to: www.kansasturfgrassfoundation.com

Water sprouts are vigorous growing, usually upright, branches that grow from dormant buds on larger branches or the trunk. They often develop after heavy pruning, though some trees are just more likely to produce water sprouts regardless. Suckers develop at the base of the tree or from the roots. Trees under stress are more likely to produce water sprouts and suckers.

It is important to remove water sprouts and suckers from the tree as they develop so the plants’ energy is not wasted on their growth. Young sprouts can be easily removed by rubbing your hand over the growth. Larger branches can be pruned away as close to the trunk as possible.

Late June through early July is garlic harvest time. When about half of the leaves have turned yellow the bulbs can be dug up. Use a broad-fork to loosen the soil and gently remove the bulbs using care to avoid bruising them. Leave the roots and leaves intact for the curing process. Tie the leaves together so the garlic is in bundles of ten and hang them in a warm, dry, well-ventilated area for several weeks. Cut the stems and roots to 1/2-inch from the bulb after curing. Remove the outer layer of skin if the bulbs are dirty, but be careful not to expose the cloves. Store the bulbs in a cool, dry location and use them within the year.

If the bulbs are dug too late the skins may start splitting and the cloves will be exposed to the soil. If harvested too early the cloves will not be fully developed.

Cross pollination is when the pollen from one flower is transported to another flower. This happens within the same plant as well as between different plants (of the same species). Cross pollination results in seeds that have genes from both parent plants. The parent plants must be from the same family, but even then, not all members of the same family will be able to cross successfully.

It is a common misunderstanding that planting two different varieties of squash next to each other will affect the type of produce harvested that year. The fruit that results from this year’s planting is determined by the mother plant. If you have purchased from a reliable seed source, the resulting produce should reflect that. If you are harvesting “weird-looking” squash, cucumbers or melons this season it is likely a result of cross-pollination that happened last year. The seeds may have been gathered from cross-pollinated plants or perhaps the plant is one that sprouted on its own after a fruit with cross-pollinated seeds decomposed in the garden last growing season.

There are several reasons why healthy vegetable crops produce flowers and no fruit. Most squash, cucumbers and melons have separate male and female flowers on each plant. Usually, male flowers appear first in the season. Female flowers have a swollen area beneath the petals while male flowers have a narrow base. Check your plants to see if both flower types are present. If male and female flowers are present, observe the area for pollinators. If few to no pollinators are present, vegetables with separate male and female flowers may not produce fruit.

You can pollinate the flowers by transferring pollen from a male flower to the stigma of the female flower using a paintbrush. Mark that flower and notice if it is the only one that sets fruit. If this is the case the problem is likely a lack of pollinators.

Pollinator activity can be inhibited by the weather. Pollinators are less active on cold and rainy days. The use of insecticides can also harm pollinators. If using herbicides, apply them in the evening when the flowers have closed for the day.

High temperatures can cause some vegetable plants to drop their blossoms prematurely. Tomatoes will stop producing fruit in temperatures above 95 degrees F. Production will resume once the temperature decreases. Ensure plants receive adequate water during this time. Though nitrogen can promote vegetative growth, too much can inhibit flower and fruit production. Follow recommended rates for fertilizer applications.

Description: Carpenter bees resemble honey bees however; the abdomen of the honey bee is covered in hairs while the carpenter bee abdomen is smooth and shiny. Female carpenter bees have a black face and a stinger, though they tend not to sting unless provoked. Males have a white face and no stinger.

Life Cycle: The life of a carpenter bee lasts one year. Adults overwinter in tunnels they bore into wooden structures. In late spring adults emerge to mate and lay eggs. Female carpenter bees make “bee bread” by combining pollen with nectar. The bee bread is inserted in one of the tunnels and females lay an egg on top of it. That section of the tunnel is sealed and the process is repeated six to ten more times. Larvae hatch from the eggs and reach maturity in five to six weeks. During late summer/early fall the mature bees emerge from the tunnels to eat for a short time before overwintering.

Damage: Carpenter bees are reliable pollinators but can be very destructive. Their tunnels are about ½-inch in diameter and five to six inches long through wooden decks, awnings and siding. The secondary damage can be even more destructive as woodpeckers peck gaping holes in the wood in search of the larvae.

Control: Carpenter bees tend to prefer soft, unpainted or weathered wood at least a couple of inches thick. Insecticides can be used to treat openings. Sevin can be applied inside the tunnels as a spray or dust. Apply on a cool night when the bees are more likely to be inside their tunnels. Treatment will need to be reapplied after one to two weeks. Carpenter bee traps can be effective for smaller populations, but to control larger populations many traps will be required for any control.

Description: Similar in appearance to other June bugs, the adult Japanese beetle is 1/4 to 3/8-inch long with a shiny, metallic-green head. The body has bronze wing covers and five clumps of hair that border the sides of the abdomen. The larvae are cream-colored grubs with a light brown head about 1 ¼-inch long at maturity.

Life Cycle: Adult female Japanese beetles lay eggs in July beneath wet lawns. Upon hatching, larvae feed on the sod roots and overwinter until the following summer. In June, the larvae pupate and adult beetles emerge to feed above-ground.

Damage: An extremely destructive pest, Japanese beetles feed on every part of the plant. The beetles skeletonize leaves and consume flowers and fruit entirely. Hundreds of varieties of plants can play host to this non-selective pest.

Control: Controlling Japanese beetles is a challenge this time of year as new adult beetles emerge from underground daily over several weeks. In small quantities, beetles can be manually removed from plants and dropped into a bucket of soapy water. Check plants daily to look for symptoms. Mornings are the best time to observe as beetles are slower and easier to catch.

There are many traps available that lure Japanese beetles into a container where the pests can be gathered and disposed of. However, some sources caution against using traps as the pheromones used to attract the beetles can draw in even more beetles than would naturally appear. Not all of these beetles may end up in the traps and the result could be greater damage to the plants.

Contact your local Extension agent for recommendations on chemical control options.

Description: There are several varieties of blister beetles. Colors vary including solid black, black with a gray or cream-colored band, and grayish-brown with yellow stripes. The relatively soft body can be up to one-inch long. They have a broad head with a narrow neck-like structure attaching it to the rest of the body. The wings are soft and the mature adult has long legs. The antennae are about 1/3 the length of the body.

Life Cycle: Adult blister beetles lay masses of eggs in the soil during late summer. When the larvae hatch, they search for nests of grasshopper eggs and begin feeding on them. Throughout several molts the larvae develop more prominent legs. The late-stage larvae are the most active and leave the grasshopper nest to pupate underground the following summer. The adult emerges 10 to 20 days later. There is one generation per year.

Damage: Blister beetles feed primarily on flowers but will consume leaves as well. Though damage can defoliate a plant entirely, blister beetles can also be great natural predators against grasshoppers. The name blister beetle is derived from the oily substance the insect emits, cantharidin, that is toxic and can leave blisters on human skin if it comes in contact.

Control: If removing manually, wear rubber gloves to protect the skin from blistering. Chemical control may be necessary for large populations. Contact your local Extension agent for support.

Description: Budworms can be brown, purple, red or green depending on the host plant it’s consuming. It has white stripes on the abdomen that run the length of the 1 ¾-inch body. There are hairs on the body as well. Adult moths are greenish-brown with a

wingspan of about 1 ¼-inches.

Life Cycle: There are two generations of budworms each year with the second generation typically being the more destructive. The pupae overwinter several inches beneath the soil surface during mild winters outdoors or in container plants that are brought indoors as well as in the soil of protected patios.

Damage: Budworms are common on petunias, geraniums, nicotiana, roses and other

ornamentals. The larvae bore a hole through the flower buds and feed on the petals. Buds may drop prematurely or, if not, the resulting bloom will show damage from the feeding. Larvae also drop black feces on the buds.

Control: Manual removal can be effective if plants are monitored regularly. Winters with

temperatures that drop below 20 degrees F can kill overwintering pupae if they are not in protected environments.

Contact your local Extension agency for recommendations on chemical controls.

Bermudagrass can make a nice lawn if you don’t mind the invasive nature and short growing season, though many homeowners do not care for these qualities. Warm-season grasses, such as bermudagrass, zoysiagrass and buffalograss, turn green later than cool-season grasses, such as tall fescue and Kentucky bluegrass. They also go dormant earlier in the fall. Bermudagrass growing in a cool-season lawn remains brown during much of the spring and fall while the tall fescue is green. Bermuda is much more drought tolerant and heat resistant than cool-season grasses allowing it to take over cool-season lawns during the summer, especially if it is growing in full sun.

Some homeowners tolerate non-uniform lawns. Those who are looking for a perfectly manicured, uniform lawn will likely have to rely on chemical treatments to eradicate weeds and rogue grass varieties. If you’re looking for the most effective way to control bermudagrass encroaching on a cool-season lawn, research has shown the use of glyphosate (2% solution, applied twice, one month apart) can work. One downside of using this treatment is glyphosate is a non-selective herbicide which means it will kill everything it contacts, including the desired turfgrass. Once the herbicide treatment is complete, the area can be re-seeded with the preferred grass species.

Glyphosate works best if the bermudagrass is growing well as this will allow it to take up more chemical through the roots. Apply the herbicide around the middle of July. Wait two weeks; mow as low as possible and remove the clippings. Wait another two weeks and spray again with glyphosate if any green remains. After another two weeks you can reseed.

Follow all label instructions and read warnings for safe handling.

Ready or not it’s time to start planning the fall vegetable garden. Fall gardens may face additional pressures of pests and heat, but the flavor that comes from these late season crops are often better. Fall planting requires attention to the number of days to harvest as well as the crops’ tolerance to frost. Crops may be direct seeded or transplanted into the garden. Growing transplants is a good choice when the temperature is too warm for starting seeds in the ground, if you have grow lights and space available for starting them indoors.

When seeding crops directly into the garden, plant slightly deeper than recommended in the spring to take advantage of the cooler soil temperatures and moisture available. Water more frequently to prevent the seeds from drying out. Overhead watering often causes soil to crust, making it more difficult for young, tender plants to emerge. Prevent this by applying a light sprinkling of vermiculite or compost over the row after seeding or use a soaker hose or drip irrigation right next to the row to allow water to slowly seep into the ground.

Plant potatoes if you can find seed stock or have saved seed potatoes. Do not use

freshly dug potatoes as they have a built-in dormancy that will prevent growth. Also, grocery store potatoes are often treated so they don’t sprout.

Cabbage, broccoli, and cauliflower can be started from seed at this time. Choose a protected place where the soil can be kept moist and rabbits will not bother them. This will not be where they will grow the entire season but these crops will be transplanted about mid-August.

Seed beets, carrots and beans.

Seed spinach and long-season maturing lettuce. Leaf lettuce will be seeded later.

Transplant cabbage, broccoli and cauliflower to their final location.

Seed radishes and leaf lettuce. No need to fertilize before planting. Side-dress two weeks after transplanting or four weeks after sowing seed by applying 2 tablespoons of a 16-0-0 or 1 tablespoon of a 27-3-3, 30-3-4 fertilizer, or something similar per plant.

The Kansas Garden Guide is a great resource for additional information about fall gardening.

When the summer heat cranks up it is tempting to add water, but this is not necessarily what the plants need. On average, vegetables need about one-inch of water per week. During a heat wave (over 90 degrees F) it may be necessary to water daily or every other day but check the soil first.

Before adding water to the garden, insert your finger one to two inches into the soil and check for moisture. If the soil is wet, wait to add water. A layer of straw mulch, several inches thick can be added to the garden in advance of a heat wave to keep the roots cooler. Ensure plants have enough water before the heat wave. It is best to water as early as possible in the morning to reduce the amount of evaporation. Drip irrigation is the best option, but regardless of the method it is important to keep water off the leaves and close to the soil.

I’ll be honest. No. I didn’t know what they were. But with some help from K-State Entomology (and of course the Google), I was able to get an ID on this intriguing sample. This is the butternut woolyworm (Eriocampa juglandis), which is a sawfly larvae. The larvae secrete a white fluffy substance and feed on their host in groups making their appearance quite unusual. When full-size, the butternut woolyworm can devour entire leaflets leaving only the veins and midribs behind. The primary host is black walnut, butternut and hickory, but trees typically recover from the short-term damage.

Cynthia Domenghini, Horticulture Instructor

K-State Plant Pathology

K-State Entomology

K-State Turf and Landscape Blog

Kansas Garden Guide

Division of Horticulture

1712 Claflin, 2021 Throckmorton

Manhattan, KS 66506

(785) 532-6173

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K-State Research and Extension is committed to making its services, activities and programs accessible to all participants. If you have special requirements due to a physical, vision or hearing disability, or a dietary restriction please contact Extension Horticulture at (785) 532-6173.

Cynthia Domenghini, Ph.D.

Instructor; Horticulture Extension Specialist

Department of Horticulture and Natural Resources

Kansas State University

1712 Claflin Rd.

Manhattan, KS 66503

785-340-3013