Insects and gardeners: It’s a long relationship, and all too often, it’s needlessly antagonistic. Very few insects are actually the enemy. Successful gardeners should learn the difference between good insects and pests, as well as how to encourage the beneficial bugs and sustainably manage the harmful ones.
“Healthy gardens are buzzing with insect life,” says Sr. Horticulturist Steve Huddleston. “Some of these insects can significantly damage plant life, but only between one and three percent are considered pests at any time in their life cycle.”
Many more insects–about seven percent–are beneficial to your garden and the ecosystem as a whole. They prey on other insects, pollinate flowers, decompose plant matter and help spread seeds. The 90 percent of remaining insects play no specific role in the garden but are part of the web of life on this planet.
The challenge for the gardener is to promote beneficial insects while discouraging the harmful ones.
Attracting Beneficial Insects
A garden full of buzzing, crawling, fluttering and burrowing bugs is a healthy garden. The most effective ways to attract insects is to incorporate the following practices:
• Grow native plants. As well as being adapted to the local climate and soils, these plants often have mutually beneficial relationships with insects common to our area. Monarch butterflies, which migrate through North Texas, feed exclusively on the milkweed plant. You can buy tropical varieties of milkweed at nurseries, but the effects of this plant on the butterfly are debated, with some authorities claiming it can spread disease and disrupt migration. Native milkweed, on the other hand, is unquestionably healthy for monarchs; look for green milkweed (Asclepius viridis), antelope horns milkweed (A. asperula), and butterfly weed (A. tuberosa).
• Provide nectar and pollen throughout the growing season. Plan your garden so that you have a succession of flowering plants blooming week after week to give pollinators like butterflies and bees nectar to eat and pollen to spread.
• Create a healthy environment. Avoid heavy use of pesticides, which will often wipe out good bugs along with the bad. Leave some leaves and mulch on the ground so insects have shady places to live, but remove large piles of dead leaves and other dead plants because they provide homes for harmful insects. Make sure you inspect plants before you transplant them into your garden. During dry spells, place a small amount water in a shallow bowl or bird bath partially filled with small rocks or gravel. Make sure you dump out the water at night to limit the spread of mosquitos.
Control Harmful Pests
• Strive to prevent infestations. Preventing pests is easier than removing them. Choose resilient plants that naturally resist disease. Repel insects with strong-scented plants such as garlic, chives and thyme.
• Handle outbreaks immediately. When you find harmful insects in your garden, it’s usually best to remove the infested plant entirely.
• Be willing to tolerate some pests. A few bugs are likely to do little harm, and plants can take some damage before they are permanently harmed. If you are growing fruits or vegetables, consider accepting some losses and less-than-perfect products for a healthier garden.
• Know your bugs. Don’t assume all insects are harmful. When you find pests on your plants, determine exactly what they are (you can find numerous insect guides online), if they are harmful and what damage they might cause. Understanding exactly what you’re dealing with will help you decide the best way to halt the damage.
• If you choose, use pesticides in a limited, targeted way. Remember that no insecticide can completely eliminate pest problems, and that sometimes their use can throw your garden ecosystem off balance and make problems worse. When you decide an insecticide is the right solution, look for a narrow-spectrum product that will target your specific type of pest. Treat only the outbreak area, and read labels carefully to select products that will not harm other insect-eating garden creatures like birds, bats, spiders and lizards.
“The next time you see a bug in your garden, remember they’re most likely your friend and not your enemy–and do your best to keep them healthy and happy,” says Huddleston.