There’s no such thing as a “pest-free” garden, no matter what people do to keep pests away. Even the healthiest gardens get pests, but too many of them can cause extensive damage and negatively affect your harvest.
Maintaining a healthy garden means, in part, identifying the most destructive bugs while also learning about earth-friendly methods of getting rid of them. Here’s a list of several common garden pests and the best ways to eliminate them.
Aphids are harmful in that they suck plant sap which, in turn, distorts foliage and causes leaves to drop. Furthermore, they secrete a sticky fluid known as honeydew that supports mold growth and attracts ants.
The easiest way to control aphids is to wash plants with a strong spray of water, covering plants when feasible, or applying garlic or pepper repellent sprays. If the problem is severe, apply insecticidal soap or horticultural oil.
Found on the crops of the cabbage family, this pest digs tunnels into the roots of plants. Control them by applying floating row covers, delaying planting, and burning roots from recently harvested plants.
Cucumber beetles are either striped or spotted, and in both cases can cause serious damage to crops by transmitting several plant diseases. Floating row covers are effective in fighting cucumber beetles, as are beneficial insects such as ladybugs, green lacewing, and spined soldier bugs. If pest levels become too high, treat plants with an organic insecticide.
Cutworms are most active at night and are found on early vegetable and flower seedlings throughout North America. They chew through stems at ground level and can completely devour small plants. You can defend against them by using cutworm collars and by delaying planting, or by removing them by hand from just beneath the soil surface.
For the most part, earwigs are beneficial but can cause damage to dahlia, clematis, and chrysanthemum flowers. Lure them away from plants with upturned flower pots filled with straw and release them elsewhere.
Flea beetles are named for the way they jump when disturbed. They hang out on most vegetable crops throughout North America and chew small, round holes into leaves, while their larvae feed on plant roots. Control them with floating row covers and by spraying plants with garlic spray or kaolin clay.
Leafminers aren’t particularly harmful to plants but the highly-visible tunnels they leave behind may reduce crop value. It’s not uncommon to find six or more of these pests per leaf. Most organic control methods help reduce leafminers and the healthier the plant, the less chance they will hurt it. Use organic fertilizers and proper watering to strengthen plants.
Spider mites attach themselves to the undersides of plant leaves and cause damage to outdoor and indoor gardens and plants. They survive by sucking material from plant cells and are particularly destructive in greenhouses. Neem oil and insecticidal soap provide protection against these nearly-invisible pests.
Another pest that’s extremely difficult to see, thrips damage plants by sucking their juices and by scraping at fruits. They lay their eggs in slits they cut in plant stems. Removing weeds and grass from around garden areas will eliminate alternate hosts of thrips, as will cleaning any debris in and around your garden. Or, use a strong spray to water to hose off plants. Ladybugs and lacewings will also destroy thrips at every stage.
Tomato hornworms may cause extensive damage to tomato, pepper, eggplant and potato plants. Though larger in size than many garden pests, hornworms are often difficult to spot because of their protective covering. However, you can control them through handpicking while beneficial insects (such as lacewings and ladybugs) attack hornworm eggs. A natural pesticide is another option, particularly when populations are high.