How to Get Rid of Cutworms in the Garden | Quick Guide to Controlling Cutworms

Unfortunately, cutworms are aptly named—their quick work on plants can completely cut them down in no time. These moth larvae, or caterpillars, are spring and summer pests that do the most damage when plants are young.

Because the moths can lay hundreds of eggs in one place, it’s important to catch or destroy them early to avoid losing a whole garden to the persistent pests.

How to know you’ve got cutworms

Most cutworms do damage at the base of a plant stalk or just under the soil. So if plants start falling over at the base without explanation, cutworms are the likely culprit.

Visual identification

Of course, seeing them will help you definitively identify your unwanted visitors, but this should be done on the sly: they come out to feed at dusk and dawn.

They’re 2-inch-long (5 cm) larvae at full maturity, and can be black, grey, or a variety of other earth tones. You’ll often see them curled up in the soil in a “c” shape.

Some cutworms are harder to identify because they venture beyond the base of the stalk: in this case, you’ll also see munch-marks in leaves and fruits of plants.

How to prevent cutworms

Regardless of whether your garden has a history with cutworms, taking steps to prevent them is a good idea.

Weed early

Moths like to lay their cutworm eggs on or around plants, so weeding thoroughly and frequently before and during the beginning of the spring season will seriously discourage them from “taking root.”

Removing weeds also cuts off young cutworms’ food supply.

Destroy their habitat

Because cutworms can overwinter, tilling at the beginning of the spring season (before planting) can either destroy their habitat or expose their presence and allow you to remove them. Tilling at the end of the season, again, allows you to expose their hiding spots, but it also allows you to remove them so they won’t be a problem next season.

How to control cutworms

Once cutworms have come to your garden, these tactics may not be enough. That’s where control and recovery from their infestation comes in.

Organic methods

There are plenty of insecticide- and pollutant-free ways to control cutworms effectively.

Invite in their natural enemy

Cutworms, like actual worms, are a beloved food for birds. You can encourage them to keep an eye on your garden by:

• Planting near a wooded area: Birds need trees for nesting and shelter, so trees will make them more likely to set up shop near your cutworm problem.
• Planting plenty of flowers: The birds like to stick around to snack on seeds.
• Plant more trees and shrubs: Birds love to roost in hedges and small shrubs. These plants also provide a source of berries, flowers, and more insects, as well as a source of protection from the wind.

Add natural deterrents to your garden

Cutworms don’t like coffee grinds and they will die if they come into contact with diatomaceous earth. Sprinkle one or both in your garden, especially around the plants, to deter or destroy cutworms.

Use a physical barrier

A seemingly archaic but totally effective solution is to place tubing around your plant stalk. Use plastic or cardboard tubes or aluminum foil around each plant as soon as you transplant it. Be sure to push your barrier of choice into the soil to deter cutworms from burrowing underneath.

This is a time-consuming but effective method: if they can’t get to your plant, they can’t eat it.

Conventional (non-organic) methods

Cutworm problems are normally not dire enough to merit pesticide use, but they are a quick and effective solution for those with limited time or an out-of-control cutworm population.

Apply your insecticide of choice to the stems of the plant or the upper offshoots and foliage, depending on where your cutworms are eating.

Make sure to buy an insecticide that’s specified as safe for your specific plant. Apply it in the afternoon or evening, right before the cutworms come out to feed, for the best results.