How to Get Rid of Cutworms

Cutworms are destructive lawn and garden pests that silently sabotage yards by cutting down young plants at the stem. Fortunately, you can get rid of cutworms with pesticides, natural solutions like beneficial nematodes, and good mowing and watering habits.

These solutions work by either infecting the pests, damaging their exoskeletons, or making the lawn a less inviting habitat.

This article provides practical strategies to identify, control, and eliminate cutworms using both natural and chemical methods, helping you restore your lawn to its former glory.

How to spot cutworms

Cutworms can be difficult to detect since they are mostly active at night, but you can spot them if you know what to look for.

What they look like

Cutworms are soft-bodied caterpillars measuring 1-2 inches long that typically curl into a C-shape when disturbed. They vary in color from gray and brown to black or greenish, often with subtle patterns. Cutworms have smooth, somewhat greasy skin, segmented bodies, and small hard head capsules, and gardeners typically encounter them in their damaging larval stage rather than as adult moths.

What cutworm damage looks like

Cutworms are most active at night, feasting on grass stems and crowns just above the soil. If you wake up to patchy, wilted grass that looks like it’s been snipped at the base, or you notice more birds on your lawn than usual, chances are you have cutworms. 

Not all cutworms cause the same damage. For instance, glassy cutworms feed on roots and stay underground, while variegated cutworms climb trees, shrubs, vines, and other garden plants to eat everything in their path. The worst damage happens when plants are still young and delicate.

It’s important to note that adult moths don’t damage grass or plants.

How to test for cutworms

If you suspect cutworms, try a simple soapy water test.

Take a tablespoon of dish soap, mix it with a gallon of water, and pour it over a small patch of your lawn in the evening. Wait a few minutes, and if cutworms are present, they’ll wriggle their way to the surface.

Also look for areas where grass blades or plant leaves look cut or wilted, then dig around the soil to see if cutworms are present.

How to get rid of cutworms naturally

Several natural methods can send cutworms packing without any harmful side effects for you or the environment.

Beneficial nematodes

Beneficial nematodes are nature’s own pest control squad. These microscopic organisms tunnel through the soil, hunt down cutworms, and enter through body openings such as the mouth or anus. Inside the cutworm, they release a special bacteria that kills the host.

• Where to buy them: Local nurseries, online retailers, and farm supply stores.
• Estimated cost: Around $20-$40 for a package, depending on the quantity.
• How fast they work: Typically, it takes a few days to see results. Longer if the infestation is large.
• What to use to apply them: A sprayer or watering can, usually mixed with water according to the instructions.
• When to use them: In early spring or late summer, when cutworms are most active and the soil is moist. To keep the beneficial nematodes effective and protect them from UV rays, spray them in the morning or evening. Otherwise, choose an overcast day.

Diatomaceous Earth

Diatomaceous earth (also called DE) is a powder made from fossilized algae called diatoms. It’s harmless to people and pets but deadly to insects like cutworms. Sprinkle it around affected areas, and as cutworms crawl over it, the tiny particles damage their exoskeletons, causing dehydration and death.

Make sure to use food-grade DE in your yard. It’s free of toxins, so it’s a safe choice for your family, pets, and the environment.

• Where to buy it: Most garden centers, online stores, and pet stores.
• Estimated cost: Around $20–$50 per bag, depending on the size.
• How fast it works: As insects come into contact with it, the full effect may take a few days to a week.
• What to use to apply it: A duster or spreader for even application. Specialty sprayers also exist.
• When to use it: During dry conditions when cutworms are active, usually in the early morning or evening when the sun isn’t as intense. Wet or damp DE doesn’t work.

Birds

A natural and effective way to keep cutworm numbers down is to encourage birds in your yard. Robins, sparrows, and other insect-eating birds love to feast on these pests as soon as they see them. 

• How to attract them: Set up bird feeders, birdbaths, and native shrubs that provide shelter year-round. Add berry-producing plants or fruit trees.

Pesticides that work against cutworms

If the cutworm infestation is severe, various pesticides can help contain it. The key is using the right product at the right time.

Bacillus thuringiensis Kurstaki (Btk)

This naturally occurring bacteria targets caterpillars like cutworms without harming beneficial insects like bees, ladybugs, and predatory beetles. The Btk strain is highly specific to caterpillars; it produces a toxin that disturbs their digestive system when ingested. 

Jodie A. Ellis, Exotic Insects Education Coordinator at Purdue University, notes that sunlight and microbes break down Btk on foliage within three to five days, so it doesn’t build up in the environment. If you’re not seeing results after those days, reapply to ensure the pests get a lethal dose.

• Where to buy it: Garden centers, nurseries, online retailers, or farm supply stores.
• Estimated cost: Around $10–$30 for a bottle. Larger quantities cost upwards of $80.
• How fast it works: Once ingested, it kills the cutworms within a few days.
• What to use to apply it: A sprayer or watering can.
• When to use it: When cutworms are young. 

Carbaryl

Carbaryl is a broad-spectrum pesticide that kills cutworms on contact and when ingested. It attacks their nervous systems, causing paralysis and death.

One big drawback with carbaryl is that it doesn’t just go after cutworms; it also harms helpful insects like bees, ladybugs, parasitic wasps, and lacewings. Even earthworms, which keep your soil healthy, can be affected. To be safe, think of carbaryl as a last resort.

• Where to buy it: Most garden centers and online stores.
• Estimated cost: Anywhere from $20 to $200, depending on the quantity.
• How fast it works: Within a few hours and stays on plants for 3 or 4 days.
• What to use to apply it: A sprayer or dust applicator.
• When to use it: Early in the season or when you first spot cutworm damage.

Bifenthrin

Bifenthrin is a fast-acting pesticide that attacks cutworms’ nervous systems, similar to carbaryl. Its effects last longer, but it also poses risks to pollinators and other beneficial insects like ladybugs and predatory beetles. With fewer natural predators around, other pests can also start multiplying, creating even more problems for you.

• Where to buy it: Garden stores, farm supply centers, and online retailers.
• Estimated cost: $15 to $30. Buying in bulk can cost around $100 or more.
• How fast it works: A few hours to a few days after application.
• What to use to apply it: Sprayer or broadcast spreader.
• When to use it: In early spring or summer when cutworms are feeding actively. Don’t use it around flowers or when pollinators are active.

Spinosad

Derived from Saccharopolyspora spinosa bacteria in the soil, spinosad targets cutworms by disrupting their nervous systems. The best part? It’s selective, so if you use it right and avoid pollinator hours, it won’t harm beneficial bugs in your yard. Due to its low toxicity, it also won’t harm your family or pets.

• Where to buy it: Garden centers, nurseries, and online shops.
• Estimated cost: $20 to $30 per bottle, though prices vary.
• How fast it works: Within 1 to 2 days.
• What to use to apply it: Sprayer or watering can.
• When to use it: Apply in the early morning or evening when pollinators are less active and when cutworms are feeding. If you have to reapply, wait at least 7 days.

Lawn maintenance practices that control cutworms

Good lawn care helps keep cutworms away, but alone, it isn’t enough to wipe out a full-blown infestation after it starts. Here are some things you can do:

Mow properly

To help shade the soil and keep cutworms from popping up, mow your lawn to the right height for its type. Don’t cut it too short (also called scalping), though; this usually stresses the grass and leaves it more susceptible to pests.

Try mowing at different times and switching your direction to disrupt their hiding spots and force them into the open. Cutworms are nocturnal, so they usually hide in the soil during the day.

My tip: In my experience, mowing a few extra times during cutworm season gives me peace of mind. It’s not a cure-all, but it definitely makes a difference.

Read more:

• When Not to Mow Your Lawn
• When is the Best Time to Mow Your Lawn?
• When Should You Mow Your Lawn in Spring?

Water correctly

If you want a lawn that can stand up to cutworms, watering the right way is key. When you water deeply and less often, you encourage the roots to grow deep and strong, making your lawn more resilient to pest attacks.

Another benefit is that it forces cutworms out of hiding, where birds and other predators can pick them off. Not sold? Water a patch of lawn right before sunset. Then, grab a flashlight and watch them wriggle on the surface.

I recommend watering about 1 inch per week (including rain) in the early morning to minimize evaporation. Don’t go overboard; soggy soil can help cutworms hide more easily. It can also attract other issues like grubs and fungi. 

My tip: After a heavy rain, walk around your yard. That’s when cutworms pop up, and you can scoop them up before they can hide again (if the infestation is mild).

Read more:

• How Long Should You Water Your Lawn?
• When and How to Water Your Lawn

Limit outdoor lighting near the lawn

Adam G. Dale, Associate Professor & Associate Chair for the University of Florida Extension, says cutworm moths are attracted to bright lights at night. His advice? Turn them off when you can, or check nearby grass for signs of cutworm activity.

Another thing you can do is use motion-activated lights around your yard to minimize moth presence, which means fewer eggs in your yard.

My tip: If you need outdoor lighting for safety, consider using red lights, which moths cannot see. 

Remove leaves and debris

Cutworms hide in leaf piles, grass clippings, and thatch during the day. If your lawn has too much of these, you’re providing cutworms with the perfect hideout. Keep your lawn clean by raking and dethatching regularly to remove their shelter. 

Aerating your lawn in the spring or fall can also keep thatch in check and promote healthier grass.

My tip: Sometimes, it’s not just about raking up leaves but about how quickly you do it. I noticed that when I left leaves on the lawn for just a couple of days, they became perfect hiding spots for pests. Aim to clear leaves the same day they fall (or at least within 48 hours) to stop any sneaky pests from moving in.

When to contact a professional

If DIY methods aren’t working and cutworms are still damaging your lawn, Lawn Love can help you find a local pest control service that will apply stronger, safer treatments to eliminate the problem.

FAQ about getting rid of cutworms

Contact a pro to rejuvenate your lawn

If cutworms took a toll on your lawn, it’s time for a comeback. Lawn Love can connect you with local lawn care experts who know exactly how to rejuvenate your lawn with aeration, seeding, fertilization, mowing, and weed control. It’s all a phone call or mouse click away.

Main Photo Credit: Diane N. Ennis | Adobe Stock