How to Get Rid of Cutworms in Your Garden

When it comes to caring for your garden, cutworms are among the nastiest and most harmful pests to encounter. They’re often mistaken for grubs, but they’re actually the caterpillar of an adult moth. The worst part of cutworms is the damage that they can cause to plants and seedlings. You may not know how to get rid of cutworms in your garden, but there are several methods to choose from, ranging from all-natural and organic to synthetic pesticides.

What Are Cutworms, Exactly?

Cutworms come in many different species but are generally on the smaller side, with a soft, pliant body about one to two inches long. The adult moths lay eggs in tall grasses, hatching in the fall. The larvae then spend winter tucked safely in the ground or other vegetative debris, like leaves or a woodpile. It isn’t until early spring that they emerge from hibernation and immediately start feasting on your garden or any plant they can find, causing lots of damage.

How To Identify Cutworms

There are a few different ways to identify these garden-destroying pests. They’re nocturnal, so try heading out around dusk since that’s when they start coming out to feed. Cutworms are also identifiable because they curl up into the shape of a “C” when they’re not actively moving or when exposed. Depending on the species, they can be almost any color or pattern, from brown to green, black, even grey or pink.

How Do Cutworms Damage Gardens?

These voracious caterpillars chew right through the base of your plant’s stems, killing them. However, they primarily eat the foliage and roots of seedlings and younger plants. The real damage they cause comes from these nocturnal pests cutting through the tops and roots of young seedlings and plants right beneath the soil. Cutworms can even destroy up to 75% of a crop when they’re present in high numbers. They’ll also devour your grass, causing extensive and unsightly brown patches on your lawn.

In fact, cutworms are so good at eating that they can work their way through sizeable areas with surprising speed, destroying entire plant systems. If you’re noticing plants that look healthy but have fallen over with the stems entirely chewed through, cutworms are most likely the culprit. In the summer, cutworms will gnaw their way through the tops of plants, though many gardeners can mistake the damage they cause, assuming it’s from slugs.

How To Get Rid of Cutworms in Your Garden

If you’ve ever walked outside to your garden and seen the beautiful seedlings that you spend months cultivating in your house fallen over and chewed through, you know how maddening cutworms can be. However, don’t automatically turn to pesticides when you have a cutworm infestation, even though it’s painful seeing your hard work and tender seedlings destroyed. There are plenty of all-natural, eco-friendly ways and tips on how to get rid of cutworms in your garden without using harmful pesticides.

Keep Your Yard Free of Debris and Leaves

The first way to prevent cutworms from taking up residence in your soil is to keep your yard and garden free of dead leaves and other debris. Cutworm larvae overwinter in things like weeds and dead plants, which double as a ready-and-waiting food source when they emerge from hibernation. By keeping your garden clean, you remove the places they need for shelter, effectively eliminating their habitat.

Cultivate the Soil Regularly

One essential tip for preventing cutworms is to cultivate your garden regularly. Tilling and working the soil is crucial for many reasons. For starters, cutworm moths lay their eggs in tall grasses, and the larvae hibernate and shelter in them. Tilling the soil will also expose cutworms and other pesky grubs, presenting them as a springtime feast for the birds. At the end of fall, till the earth and mow to eliminate their winter home.  

Wait to Transplant or Start Seedlings

Cutworms emerge from hibernation very early in the growing season. If you wait to transplant or sow seeds, you could miss their emergence. That way, they’ll have a harder time finding food when they come out of hibernation instead of waking up to an easy meal that you provided for them. By waiting as late as possible, you can starve them out before they have a chance to ruin your beautiful garden.

Add Diatomaceous Earth to Your Garden

Diatomaceous earth is an organic type of soil that’s made from the fossilized remains of diatoms, which are microscopic organisms present in fresh and saltwater. Using diatomaceous earth is how to get rid of cutworms quickly and efficiently, as it kills insects with soft bodies. However, it may also kill vital pollinators like bees, so use it with caution and apply it sparingly.

Give Your Plants Collars

Another creative method for preventing cutworms is using plant collars. If you’ve got the budget, you can buy them online. If you’re a little more on the frugal side, you can make your own out of recycled toilet paper tubes or the top half of a milk jug/soda bottle. If you’re using toilet paper rolls, cut them in half and carefully place the seedlings inside. Plant it with the tube about two inches below the soil and two inches above.

Use the “Pluck and Squish” Method

This technique may be a little on the gruesome side, but it sure is effective. Remember, cutworms are nocturnal. If you go out during the day, they’re hiding underneath the soil, but you can dig down an inch or two and find them. Or, wait for dusk, head out to your garden with a flashlight, and pluck to your heart’s content. They’re pretty soft, so try using two rocks to squish them. If you’re squeamish, you can just drop them in a bucket of soapy water.

Place Nails or Wooden Kebabs on Your Plants Stems

Cutworms awake from hibernation ravenous and chew through stems by curling or wrapping around them. An excellent method to get rid of cutworms in your garden is to take something hard like nails, toothpicks, or wooden kebabs and place it in the soil next to the plant stem. This method is best suited for larger plants, like tomatoes. By protecting the stems, the cutworms cannot wrap around them to chew through.

Sprinkle Coffee Grounds Around Your Plants

Another all-natural method for repelling cutworms from your carefully nurtured garden is sprinkling coffee grounds around the base of your plants. If you don’t drink coffee, you can also use crushed eggshells in the same way. Or, try oak leaves or damp wood ashes spread around your garden.

Apply Insecticide

Though you may not want to apply insecticides, they will effectively eradicate a cutworm infestation. One popular and natural insecticide is Bacillus thuringiensis, which should be used in the late afternoon for the best results. Unfortunately, Bacillus thuringiensis can harm butterflies, which are not only critically important pollinators but thrilling visitors to see in your garden. So, please use caution before applying this insecticide.

Another insecticide you can try is carbaryl, which is the name for 1-naphthol N-methylcarbamate. It comes as a solid or crystals, or as a fine dust only sold under the brand name Sevin, called Sevin Dust. However, carbaryl is a wide-spectrum insecticide, so use it in moderation or only under dire circumstances—it can also kill beneficial insects and pollinators vital to a healthy and thriving garden.

Let Them Gorge on Cornmeal

One of the most cost-effective and organic methods for eliminating a cutworm infestation is by sprinkling copious amounts of cornmeal in your garden. The insatiable cutworms absolutely love cornmeal, and they’ll gorge themselves happily. However, their bodies cannot digest it, and they’ll perish from overeating.

Try an All-Natural Mixture

Head to the kitchen for this tip on how to get rid of cutworms. Make a mixture of molasses, wheat bran, water, and wooden sawdust. Combine the ingredients thoroughly and then encircle your plants (use gloves!) with the goopy mixture. When the cutworms emerge from the soil to chow down on your meticulously nurtured plants, the sticky mixture will harden on their bodies, essentially paralyzing them.

Cutworms are one of the most harmful pests to find in your garden. A cutworm has one purpose in life: destroy and consume every plant you’ve carefully reared from seed and transplanted with care. However, there are plenty of all-natural methods and creative tips for preventing cutworms or eliminating an existing infestation. You can try using plant collars, sprinkling coffee grounds, or even picking them by hand with a flashlight.

If you’re really serious about removing a cutworm infestation, you can use pesticides, but please use them with caution. Depending on which kind you choose, you could end up harming other beneficial insects and pollinators. However, any of those methods will help you maintain a flourishing garden free of cutworms. Keep up with Amaral Farms for more tips!