How to Stop Grasshoppers in Your Garden from Eating the Plants

Gardeners and grasshoppers are rarely on friendly terms. An outbreak (when swarms of insects hatch and begin feeding at the same time) can devastate a small garden in just a few hours. Huge appetites, combined with the ability to easily jump or fly from plant to plant, make grasshoppers one of the most destructive garden pests. They're also one of the toughest insects to control, since they move so quickly, thanks to their big back legs and active wings. Not only do they readily move between plantings in one landscape, but they can cover great distances as they move from one neighborhood to another. Learn how to combat a grasshopper outbreak with these tips.

How to Spot Grasshoppers in Your Garden

Grasshoppers are common throughout the U.S. You might see them in shades of green, gold, or brown. They chew ragged-looking holes in plant leaves. In some areas, they begin feeding in early summer and continuing devouring foliage until the first hard frost in fall, becoming more numerous as the season wears on. There are more than 100 types of grasshoppers, and they eat all kinds of plants. Some species eat weed plants and grasses with little garden value, while other species feast on vegetable crops, such as lettuce, carrots, beans, and corn, along with prized perennials.

Most grasshoppers emerge in the spring from eggs laid the previous fall. A cool, wet spring will destroy many of the hatchlings. A dry spring also presents challenges, because there's often not enough plant growth for the hatchlings to survive. Weather conditions at the time of the hatch have a significant impact on how many of the insects will invade your garden.

How to Control Grasshoppers

Grasshoppers invading your garden doesn't mean all your plants are goners. Here's how to control their numbers, and prevent them from taking over.

Attract Beneficial Insects and Other Garden Predators

Plant flowers, such as marigolds, calendula, sunflower, aster, alyssum, or dill to attract beneficial insects, like robber flies. A few other garden predators, such as spiders and toads, will also help keep grasshoppers under control.

Create a Bird-Friendly Garden

Many birds, such as kestrels and larks, eat large quantities of grasshoppers. Provide a water source and nesting habitat to encourage birds to take up residence in your yard. A diverse selection of native trees and shrubs will also attract birds.

Natural Grasshopper Control

A grasshopper disease called Nosema locustae can slowly kill the pests. It's available as a dry, flaky product under the label Nolo Bait, which you can apply to areas where grasshoppers lay their eggs. It's important to reapply it after a rain. It's most effective on young grasshoppers, but not all grasshopper species are susceptible to the disease. Another option is a garlic-based repellent ($16, Arbico Organics).

Insecticides

If you choose to use insecticides, there are a couple of important points to know. First, insecticides don't offer complete control because grasshoppers travel so much that the products you use may not kill them until after they've done their damage to your garden and moved on to someone else's. Also, insecticides won't keep new grasshoppers from coming into your garden. And the products that kill grasshoppers also kill beneficial insects, so use them with extreme caution. Look for products containing carbaryl or permethrin. Apply insecticides when the eggs begin to hatch in May or June, the time when they're young and less mobile.