Say Goodbye to Garden Weevils With These 7 Natural Remedies That Work

Weevils are a type of beetle identified by their round bodies and long snouts. These insects typically thrive on eating the leaves and roots of your favorite edible and ornamental landscape plants. With thousands of different types of weevils spread throughout the world, nearly every lawn and garden has its own population.

In most cases, natural predators—like birds, spiders, or rodents—keep weevil populations under control. But signs of large-scale damage, like wilted plants, stunted growth, yellow leaves, or gnawed leaf edges, could indicate a problem. "Adult weevils chew irregular notches into the edges of leaves, creating a 'scalloped' or jagged appearance," says David Holmes, director of systems at Lawn Pride, a Neighborly company. While this might not kill the plant immediately, it weakens it and makes it more susceptible to disease. "Larvae are even more destructive—they live in the soil and feed on the roots of plants," he says.

Weevils can cause significant damage to ornamental and edible plants, making them a nuisance for gardeners. Ahead, we're sharing the most common types of weevils and the best ways to get rid of them. 

Common Types of Weevils

Scientists have identified more than 50,000 species of weevils. "While some might associate 'weevils' with flour and other grain products, other kinds of these so-called snout beetles (many have a prolonged head) can be found on landscape plants as well," says Daniel Gilrein, extension entomologist at Cornell Cooperative Extension of Suffolk County. "Most are not significant pests, and they’re often unnoticed with coloring that often matches their surroundings or because they reserve activity for after dark."

Some of the most common types of weevils our experts have come across in their work include:

• White pine weevil: One of the more damaging kinds, this one attacks the latest season’s top terminals of eastern white pine and some other conifers, causing dieback and leaving a characteristic 'shepherd’s crook' wilted shape," says Gilrein.
• Plum curculio: These weevils infest developing stone or pome fruits, like plums, peaches, apples, pears, and quince, says Gilrein. "Some infested fruit will drop in spring. Promptly collecting and destroying these undeveloped fruit or exposing them to full sun should provide some control."
• Twobanded Japanese weevil: These 1/4-inch-long weevils are identifiable by two dark bands across their gray body and by the notches they leave in lower leaves of shrubs like lilac, forsythia, privet, or spirea, says Gilrein. "Usually, the feeding damage on leaves is insignificant, and plants generally thrive just the same." He adds that the beetles can be collected by hand if they are a problem.
• Black vine weevil: These black weevils prefer to eat landscape shrubs and herbaceous perennials, including yew, arborvitae, azalea, rhododendron, astilbe, and coral bells, says Gilrein. He adds that the immature stage is a small white grub. Luckily, these weevils haven't been as much of a problem for gardeners in recent years, thanks to natural enemies (like birds).
• Billbugs: Billbugs are a type of weevil that can damage landscapes by attacking cool- and warm-season grasses, says Kyle Wickings, associate professor in the Department of Entomology at Cornell AgriTech. These bugs lay eggs in spring in grass sheaths; after hatching, the larvae burrow into the soil and eat the roots of turfgrass. Wickings recommends setting out cups filled with dish detergent and water to capture these insects. 
  

How to Get Rid of Weevils

It's rare for weevils to cause major damage in a residential landscape, says Keri Wilson of Garden Media Group. "Weevils are generally not harmful to humans or pets; they do not bite, sting, or transmit diseases," she says. "Finding a few weevils in your yard isn’t a cause for concern. A healthy landscape will have natural predators to keep weevil populations in check."

However, some weevil populations do cause problems for backyard gardeners by chewing on leaves, destroying underground root systems, and targeting edible gardens, says Holmes. Manage your weevil residents with these natural methods.

Introduce Beneficial Nematodes

Adding beneficial nematodes to your soil can help control weevil infestations. "These microscopic organisms actively hunt and kill weevil larvae in the soil," says Holmes. "Applying them to your yard can significantly reduce weevil populations before they mature into adults and cause visible damage. Apply them in the evening or on a cloudy day, following the package instructions; they're especially effective against root-feeding weevils."

Remove Plant Debris

Make it harder for weevils to thrive in your yard by removing the food and shelter they rely on. "Weevils are attracted to fallen fruits, nuts, and decaying plant matter," says Holmes. "Regularly clean up your yard by raking leaves, removing fallen produce, and keeping mulch thin to reduce hiding places and food sources for weevils."

Try Companion Planting

Companion planting is a natural way to improve the health of your landscape. Choose aromatic herbs that make your garden less inviting to weevils. "Some herbs, like bay leaves, garlic, and mint, are natural weevil deterrents," says Holmes. "Planting these around your yard or garden borders can help repel weevils due to their strong scent." Note that you should only plant mint in containers as it can take over the garden quickly.

Remove Adult Weevils

To manage a minor weevil population, remove individual insects by hand after sunset. "Adult weevils are most active at night," says Holmes. "You can shake infested plants over a sheet or tarp in the evening and manually remove the insects. It’s time-consuming but effective for smaller infestations."

Implement Sustainable Gardening Practices

Focus on pesticide-free treatments and avoid invasive plant species to create a garden balanced for your regional ecosystem, says Wilson. “The best way to keep weevil populations in check is to eliminate pesticide use in the landscape and plant densely with diverse species of native plants, which will naturally attract beneficial insects and other small wildlife predators, such as birds,” she says.

Remove Infested Plants

For a more intense infestation of weevils, you may need to cut back or remove the plants they’ve overtaken. "Trim heavily infested areas and dispose of the cuttings far from your yard," says Holmes. "Removing hiding spots helps reduce the weevil population and prevents them from spreading."

Use Diatomaceous Earth

Food-grade diatomaceous earth is a natural pest repellent that is safe for humans and pets. Sprinkle it around plants in your garden to kill insects. "It works by damaging the exoskeletons of weevils, causing them to dehydrate and die," says Holmes. (Remember that, as with other bulk-application approaches, you won’t just be targeting the weevils in your yard; you’ll affect other insect populations, too.)