By Marty Ross
We have our share of insect pests in the Midwest, but remember, not all bugs are bad. It’s important to make insects welcome in your garden—without bees and other pollinators, we wouldn’t have all the fruits and vegetables we love.
A healthy garden has a natural balance between good and bad bugs. But you have to be vigilant to tell the difference and prevent serious problems. When cross-striped cabbage worms (see above) move in on the kale crop, it’s time to step in.
An infestation of cabbage worms can consume more kale than a human family of four! If you see holes in the leaves, look for caterpillars—usually found on the undersides of the leaves. Pick off the caterpillars and squish them. It doesn’t take long, and if you catch the infestation early, you can stay on top of it.
If the larvae population is well advanced, reach for Bt (Bacillus thuringiensis), an organic insecticide approved for organic gardens. When the larvae eat leaves sprayed with Bt, they stop feeding, and the poison kills them within 48 hours. You can find Bt at Lowe’s. It gives the kale a chance to rebound, and you’ll have a great harvest.
Bt is not toxic to humans and other animals. It does not harm butterflies or bees. But wear gloves when you use it, and wash your hands and your spray equipment after use.
Squash bugs are another threat to the summer harvest. The nymphs hatch from beautiful clusters of luminous red eggs, usually found on the undersides of leaves. Squash bugs suck on leaves and cause them to wilt and die. The best and easiest way to control them is to check your squash plants every day, beginning just when the plants start to flower. Look for the eggs, and crush them with your fingers. If you see nymphs, pick them off and drop them into a pail of soapy water. It’s time well spent.
Not all caterpillars bring bad news. My garden is a Monarch Waystation, and I grow butterfly milkweed, coneflowers, lantanas, verbena, zinnias, sedums, and other flowers monarch butterflies love. The butterflies lay their eggs exclusively on butterfly milkweed. Their larvae, which are beautiful striped caterpillars, eat the milkweed leaves and grow at an astonishing rate.
Butterfly milkweed is a beautiful plant, and I don’t mind sharing. The Midwest is an important habitat for monarch butterflies. They need our help. Plant a few extra milkweed plants this year, and you have the added pleasure of growing your own butterflies. Even if the caterpillars eat all the leaves of your butterfly milkweed plants, this perennial comes back next year, bigger and even more vigorous than before.
The larvae of yellow and black swallowtail butterflies eat plants in the parsley family. You see their tiny eggs and larvae on the leaves of dill, parsley, fennel, carrots, parsnips, and Queen Anne’s lace. These butterflies add a lot of life to the garden, so plant more parsley than you need—don’t run out! Planting parsley is a sure way to increase your backyard’s butterfly population.
In some neighborhoods, rabbits and deer number among the most destructive pests. One way to check damage is to cage important plants with poultry fencing (sometimes called chicken wire, available at Lowe’s). Spraying plants with repellent also does the trick.
Repels-All (sold at Lowe’s) smells really bad when you spray it—and it must taste worse, because a good spritz with this ready-to-use repellent ensures that deer and rabbits do not nibble. Spray plants lightly. Your daylilies, lilies, and rose buds will live to bloom, and your asters will grow and thrive. The tender foliage of newly planted trees will not become a salad bar for deer.
Use pesticides judiciously and only when necessary. You’re in a partnership with nature. There has to be a little give and a little take.
Find out what our 10 regional gardening experts are dealing with these days—pests, viruses, and even beneficial insects.Learn More