Control squash bugs nymphs with recommended insecticides

Chris Himmelwright
Pratt Tribune
Squash bug nymphs grow into nasty garden pests.

Squash Bugs

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.

Planting Winter Squash and Pumpkins

Now is the time to plant pumpkins and winter squash so they don’t try to mature fruit during the heat of summer but rather in early October. Fruit that matures during hot weather may shrivel and lose quality. These plants take up a lot of room so place a seed or two ever 2 feet apart in the row with about 8 to 10 feet between rows. Seeds should be planted 3/4 to 1 inch deep. Keep watered until the plants emerge which usually takes about a week. Gradually back off watering as the plants become established. Winter squash and pumpkins love the heat and so should do well this year.

Pinching Mums Though some garden mums do not require pinching back, most varieties will benefit. Pinching is done by removing the top inch of growth by pinching it between your thumbnail and forefinger. You can also use a scissors or even a pair of hedge shears. Pinching encourages lateral buds to break and grow

resulting in a shorter, sturdier and fuller plant. The first pinching is usually done when the mums reach six inches in height. Remove about the top inch of growth. A second pinching should be done when the new growth from the previous pinch reaches about 4 inches. Cut the new growth down by about half. We may have time for one more pinch but maybe not as the last pinch should take place around July 4. Pinching later than July 4 can delay flowering resulting in a shorter time of flowering before frost kills the blooms. You may find a video on pinching mums helpful. It is found on our Kansas Healthy Yards website.

Deadheading Flowers

Some plants will bloom more profusely if the old, spent flowers are removed, a process called deadheading. Annuals especially, focus their energy on seed production to insure that the species survives. If you remove old flowers, the energy normally used to produce seed is now available to produce more flowers. Perennials can also benefit by lengthening the blooming season. However, some gardeners enjoy the look of spent flowers of perennials such as sedum or purple coneflower. Also, the seed produced can be a good food source for birds. Not all plants need to be deadheaded, including sedum 'Autumn Joy', melampodium, impatiens, most flowering vines, Lythrum, periwinkle (Catharanthus), and wishbone flower (Torenia). Those that do increase bloom in response to deadheading include hardy geraniums, coreopsis, petunias, marigolds, snapdragons, begonias, roses, campanulas, blanket flowers, delphiniums, zinnias, sweet peas, salvia, scabiosa, annual heliotrope, geraniums (Pelargonium), and yarrow. Deadheading is easily accomplished by removing spent flowers. With some plants, pinching between a thumb and finger can do this, but tough, wiry stems will require a scissors or pruning shears.

Adapted from the Kansas State Horticulture Newsletter