How to Stop Flea Beetles from Devouring Your Garden for Good

Flea beetles can wreak havoc in the garden. These insects are recognized by their tiny, shiny bodies that are about the size of a sesame seed. They are typically black, bronze, or a dark metallic blue, with some species having stripes or spots. The easiest way to identify flea beetles is by their large black legs, which they use to jump, similar to fleas.

These small beetles are especially dangerous to vegetable gardens and seedlings, as they chew small, round holes in leaves. The holes weaken plants, stunt their growth, and can kill seedlings. Flea beetles can also spread diseases like bacterial wilt and fungal blight, affecting crops like radishes, eggplants, tomatoes, and cabbage.

If you're dealing with flea beetles in your vegetable garden, we spoke to experts who shared their tips for getting rid of these insects and preventing them from returning.

How to Get Rid of Flea Beetles

While a few holes in plants aren't something to worry about, an infestation of flea beetles can be devastating. If you have a surplus of these insects in your garden, use these expert-approved methods to banish them once and for all.

Apply Diatomaceous Earth

Diatomaceous earth is an effective, all-natural pest repellent. "The natural powder, made from crushed fossilized algae, scratches and dehydrates flea beetles when they crawl over it," says Shannon Harlow-Ellis, associate certified entomologist and technical services manager with Mosquito Joe. "Homeowners can apply a light dusting on dry leaves and around plant bases."

Plant Trap Crops

Trap crops will lure flea beetles away from the desirable plants you want to harvest. "As vast as their appetite is, flea beetles are drawn to plants in the brassica family, so growing plants like radishes, mustard greens, and kale nearby as trap crops to attract flea beetles away from your main crops is a common and effective strategy," says Timothy Wong, technical director at M&M Pest Control.

Encourage Nematode Populations

Nematodes are microscopic worms that live in the soil and attack pests like flea beetle larvae, reducing the number of adult beetles that emerge in spring. "To encourage them in your garden, keep the soil moist and rich in organic matter, and avoid chemical pesticides that could harm them," says Wong. "You can also buy and release nematodes from local garden suppliers or online, applying them to damp soil in the early morning or evening, and minimizing tilling to protect their populations."

Use Neem Oil

Neem oil is a natural insecticide that disrupts the feeding and reproductive cycles of beetles. "Neem oil is derived from the seeds of the neem tree and breaks down quickly in the environment. You can buy it at garden centers, hardware stores, or online retailers," says Wong. It is usually sold as a concentrated liquid that is mixed with water and sprayed onto plants. 

Attract Natural Predators

Flea beetles have several natural predators that will help keep infestations under control. "Ladybugs, lacewings, and predatory beetles can help control flea beetle populations naturally by feeding on their eggs and larvae," says Wong.

How to Prevent Flea Beetles

Once you've eradicated flea beetles from your garden, use these methods to prevent them from coming back and damaging your crops.

Plant Pest-Repelling Crops

There are several crops that can prevent flea beetles from taking up residence in your garden, including catnip, basil, thyme, and marigolds. "These strongly scented plants can repel flea beetles and mask the scent of target crops," says Ankit Singh, assistant professor and ornamental horticulture educator at the University of Maine Extension.

Use Row Covers

Row covers create a physical barrier between the beetles and your crops, while still allowing sunlight and moisture to reach your garden. "They should be installed immediately after planting to help prevent infestations," says Harlow-Ellis.

Apply Mulch Barriers

Apply a thick layer of mulch around plants to block flea beetles from reaching seedlings and deter them from laying their eggs in the soil, says Wong. Keep the mulch a few inches away from the stems and branches of your plants to prevent rot.

Practice Early Planting

According to Wong, planting seedlings early in the season can help them establish before flea beetle populations peak, making them less susceptible to serious damage. Singh says another option is to start seedlings indoors to keep them away from these hungry insects.

Clean Beds in Fall

Once gardening season is over, Singh says to remove excess plant debris and clean up gardening beds to prevent flea beetles from overwintering in your yard.