Pests in Your Summer Garden
Fewer nibbles from them means more nibbles for you
It’s finally summer and as your garden begins to produce, you’ll quickly realize that you’re growing veggies and fruit not only for yourself and your family, but for your garden pests as well. Before you reach for a chemical cocktail to banish the bugs, consider IPM, or Integrated Pest Management.
“IPM uses lots of little hammers that do lots of little jobs to knock out pests,” says Thomas Prohl, production educator at Wolfe’s Neck Center for Agriculture & the Environment in Freeport, Maine. “It’s a system of cultural, biological, and mechanical controls, with an emphasis on prevention, that farmers and gardeners use to manage pests and optimize the health of their plants.”
Prevention is the first tool in the IPM toolbox. After all, the pest or disease that you don’t have is the best kind. IPM prevention strategies range from using row cover to thwart damaging insects from landing on their favorite food plants to ensuring that your soil and plants are healthy enough to withstand the inevitable attack. A healthy plant can fight off a disease more effectively than a weak plant, much like healthier people can withstand and recover from a cold or flu with less impact than weaker people.
Be realistic about how much pest damage you can tolerate before resorting to chemicals. Rather than trying to kill every single insect pest and pull every weed, watch your plants and observe how they do with some insect damage. Healthy pole beans can take a fair hit when the Japanese beetles come to town and a few weeds around the base of your tomato plant won’t rob ALL of the nutrients from your Sun Golds.
When pests or disease do appear, though, and you discover an infected plant, such as a tomato with early blight, pull it immediately, bag it in plastic, and throw it away with the trash. Do NOT put it on your compost pile, where the disease likely will live on and find its way on the wind to other plants.
Pay careful attention when you purchase plants or accept gifts of plants from neighbors or friends. You might find that you’re the new owner of an invasive weed such as Bishop’s weed, or a disease such as a fungus or scab. If you borrow tools, be sure to wipe them down with a mixture of 10% bleach to 90% water and regularly sterilize your own tools and wash your plant pots to avoid disease transmission
In addition to these prevention methods, you should also practice cultural controls— the bedrock of IPM—including rotating crops to confuse pests, limiting soil compaction, and orienting your plants to make the best use of sunlight. If you mulch with straw, check it for pests or mold before spreading it on your garden.
And, says Prohl, “Spend time in your garden! There’s so much that you can learn from being in your garden. Know your plants—scout the stems and the underside of leaves daily for pest eggs and rub them off with your fingers. Learn about the predator/prey relationship and plant perennials that feed the beneficial insects that will feed on common garden pests.”
These beneficial insects are your friends in the fight against pests and serve as biological controls. Ladybugs, for instance, will eat huge quantities of aphids and look for pollen as a food source. You’ll attract them with flowers and herbs including dill, fennel, yarrow, tansy, scented geraniums, coreopsis, and cosmos.
Many pests overwinter in your garden, so be sure to keep the edges free of debris—leaf litter, piles of weeds, or grass clippings—to remove their habitat.
If pests do mature, use the mechanical controls of IPM such as simply picking them off of the plant and dropping them in a can of water with a little dish soap. (Chickens love to eat tomato horn worms; save them for your neighbor’s chickens and enjoy some eggs later on.)
Integrated pest management offers the home gardener a variety of tools to use in the quest for a healthy home garden. Take a walk through your garden and determine which of these techniques you’re using already and which you can add to your repertoire. Give your garden its best chance to thrive this summer.
“The chemicals that some home gardeners are pulling off the shelf are some high-test stuff,” cautions Prohl. “You’re feeding your family with this stuff. IPM is a really fun way to use science in the garden to grow healthier, more wholesome food for your family.”
Top Five Pests to Look Out for in Your Summer Garden
Striped cucumber beetles attack plants such as on squash, cucumber, and pumpkin in two different ways. The adult beetle will munch through the lower surface of leaves and can spread disease, while the larvae damage the roots. Organic pyrethrum can be effective, along with handpicking the adult beetles daily. Row cover will prevent them from reaching your plants, but be sure to remove the row cover by midsummer when pollination occurs.
Japanese beetles are easy to spot because of the characteristic damage they do to plants, chewing the leaves to a lacy pattern, and by their metallic coloring. Employ consistent handpicking, neem oil spray, and row cover to manage this pest.
Squash bugs will destroy your zucchini plants if you don’t get ahead of them. Check the undersides of the young plant leaves daily and rub off the orange eggs with your thumb. Use a neem oil spray, reapplying after rain, and you’ll keep their numbers down.
Cabbageworms and cabbage moths will eat your cabbage, kale, and collard greens, so protect the seedlings with row cover to prevent the moth from laying eggs and spray with neem oil.
Aphids are small, soft-bodied insects that multiply rapidly, sometimes covering the entire surface of a plant’s stem or leaf. A potential vector of viruses, aphids are a tasty treat for ladybugs and lacewing larvae. Ladybugs like sugar and you can encourage them to hang around your garden with small amounts of honey or sugar. If you have a serious aphid problem, you can order ladybugs or adult lacewings ready to lay the eggs that will become a voracious aphid predator.
Debbie Atwood gardens in Brunswick, Maine, and graduated with the Cumberland County Master Gardener Class of 2004.