Cutworms hide just beneath the soil surface during the day, then emerge at night to sever young seedlings at the stem. If you have ever walked out to your garden in the morning to find your prized tomato or pepper plants lying flat on the ground, you have likely met these sneaky pests. So, how do you get rid of cutworms before they destroy your entire vegetable patch? The answer involves a mix of prevention, physical barriers, and natural controls that work together to stop these caterpillars in their tracks.
Cutworms are not actually worms—they are the larvae of several species of night-flying moths. They curl up into a C-shape when disturbed, which is how they got their name. These pests target a wide range of plants, including beans, corn, lettuce, and flowers. The good news is that you can fight back without harsh chemicals. Below is a complete guide to identifying, preventing, and eliminating cutworms from your garden.
Identifying Cutworm Damage And Life Cycle
Before you take action, you need to be sure cutworms are the problem. Look for these signs:
- Seedlings cut off at the base, as if snipped with scissors
- Plants that wilt or fall over suddenly
- Small holes in leaves or fruit near the soil line
- Curled, grayish or brown caterpillars hiding in the top inch of soil
Cutworms overwinter as eggs or young larvae in soil or plant debris. In spring, they become active and feed voraciously for several weeks. They pupate in the soil, then emerge as moths in early summer. The moths lay eggs on weeds or crop residue, and the cycle repeats. Understanding this timeline helps you time your control methods for maximum impact.
Common Cutworm Species In Gardens
There are many species, but the most common ones include:
- Black cutworm (Agrotis ipsilon)
- Variegated cutworm (Peridroma saucia)
- Dingy cutworm (Feltia jaculifera)
- Bronzed cutworm (Nephelodes minians)
All species cause similar damage, so you do not need to identify them exactly to control them. Focus on the symptoms and the timing of their activity.
How Do You Get Rid Of Cutworms
This section covers the most effective methods to eliminate cutworms from your garden. Use a combination of these strategies for the best results.
Physical Barriers And Collars
One of the simplest and most reliable methods is to create a barrier around each seedling. Cutworms cannot climb over or chew through a solid collar. Here is how to do it:
- Cut strips of cardboard, plastic cups, or aluminum foil about 3 inches wide and 6 inches long.
- Form each strip into a cylinder that fits snugly around the stem of the plant.
- Push the collar 1 to 2 inches into the soil, leaving 1 to 2 inches above ground.
- Repeat for every seedling you transplant or direct sow.
These collars stop cutworms from reaching the stem. They are cheap, easy to make, and last for the entire growing season. Remove them when plants are large and woody, usually after 3 to 4 weeks.
Handpicking At Night
Cutworms are nocturnal, so the best time to catch them is after dark. Arm yourself with a flashlight and a small bucket of soapy water. Go out to your garden an hour after sunset and look for cutworms on the soil surface near damaged plants. They often curl up when disturbed. Pick them off and drop them into the soapy water. Repeat this every night for a week to significantly reduce the population.
This method works well for small gardens. It is labor-intensive but chemical-free and highly effective if you are consistent.
Beneficial Nematodes
Beneficial nematodes are microscopic roundworms that parasitize and kill cutworms. They are a natural, soil-dwelling predator that targets many soil pests. Apply them in the evening when the soil is moist and temperatures are above 50°F. Mix the nematodes with water according to package instructions and spray the soil around your plants. They will seek out cutworm larvae and infect them, killing them within a few days.
Look for species like Steinernema carpocapsae or Heterorhabditis bacteriophora. These are widely available online or at garden centers. They are safe for pets, people, and beneficial insects.
Diatomaceous Earth
Diatomaceous earth (DE) is a powder made from fossilized algae. It has sharp edges that cut into the soft bodies of cutworms, causing them to dehydrate and die. Sprinkle a thin layer of food-grade DE around the base of each plant and on the soil surface. Reapply after rain or heavy watering. Wear a mask to avoid inhaling the fine dust.
DE is most effective when dry. It works best as a preventive measure or for light infestations.
Bacillus Thuringiensis (Bt)
Bacillus thuringiensis is a naturally occurring bacterium that produces a protein toxic to caterpillars. It is sold as a spray or dust. Apply it to the soil and lower leaves of plants in the evening. Cutworms ingest the bacteria when they feed, and it stops them from eating within hours. They die in a few days. Bt is safe for humans, pets, and beneficial insects like bees and ladybugs.
Use a product labeled for cutworms. Apply it every 5 to 7 days during active feeding periods.
Preventing Cutworms Before They Arrive
Prevention is always easier than cure. Here are steps you can take to make your garden less inviting to cutworms.
Remove Weeds And Debris
Cutworm moths lay eggs on weeds and plant debris. Keep your garden clean by removing weeds, old mulch, and leftover plant material in fall and spring. This removes potential egg-laying sites and reduces overwintering habitat.
Delay Planting
If possible, wait until the soil warms up in late spring before planting. Cutworms are most active in cool, moist soil. Planting after the soil temperature reaches 60°F can reduce the risk of severe damage. This also gives your seedlings a faster start.
Use Row Covers
Floating row covers are lightweight fabric sheets that let in light and water but keep moths out. Place them over newly planted beds and secure the edges with soil or rocks. Remove the covers once plants are large enough to withstand some feeding, usually after 3 to 4 weeks.
Attract Natural Predators
Encourage birds, ground beetles, and parasitic wasps to visit your garden. These creatures eat cutworms. Provide bird feeders, birdbaths, and native plants that attract beneficial insects. Avoid broad-spectrum insecticides that kill these helpers.
Organic And Chemical Control Options
If natural methods are not enough, you can turn to organic or chemical options. Use them as a last resort and follow label instructions carefully.
Organic Insecticides
Products containing spinosad or neem oil can kill cutworms. Spinosad is derived from soil bacteria and is effective against caterpillars. Neem oil disrupts feeding and growth. Apply these in the evening when cutworms are active. They break down quickly in sunlight and are safe for most beneficial insects when used correctly.
Chemical Insecticides
Synthetic insecticides like carbaryl (Sevin) or permethrin can kill cutworms quickly. However, they also harm pollinators and other beneficial insects. Use them only for severe infestations and apply them directly to the soil around the plant base. Avoid spraying flowers or open blooms. Always wear gloves and follow safety precautions.
Long-Term Garden Management
Cutworms can return year after year if you do not break their life cycle. Here are long-term strategies to keep them under control.
Crop Rotation
Do not plant the same crops in the same spot every year. Cutworms often specialize in certain plants. Rotating your crops confuses them and reduces their numbers. Wait at least three years before planting the same family of vegetables in the same bed.
Fall Tilling
In late fall, till your garden soil to a depth of 6 to 8 inches. This exposes cutworm eggs and larvae to birds and cold weather. It also destroys overwintering sites. Avoid tilling in spring if you use no-till methods, as this can disturb beneficial soil life.
Companion Planting
Some plants repel cutworms or attract their predators. Plant garlic, onions, or marigolds near susceptible crops. Dill and fennel attract parasitic wasps. These plants do not eliminate cutworms entirely but can reduce their impact.
Frequently Asked Questions About Cutworms
What Is The Fastest Way To Get Rid Of Cutworms?
The fastest method is handpicking at night combined with applying Bt or diatomaceous earth around the plants. This gives immediate results and stops further damage within 24 hours.
Can Cutworms Kill Mature Plants?
Cutworms mostly target young seedlings. Mature plants with woody stems are less vulnerable. However, some species climb and feed on leaves or fruit, which can weaken older plants.
Do Coffee Grounds Repel Cutworms?
There is no strong evidence that coffee grounds repel cutworms. They may help improve soil structure, but they are not a reliable control method. Stick with proven barriers and nematodes.
How Deep Do Cutworms Burrow In Soil?
Cutworms typically stay in the top 1 to 2 inches of soil during the day. They can burrow deeper in cold weather or when disturbed. This is why shallow tilling can expose them.
Will Vinegar Kill Cutworms?
Vinegar can kill cutworms on contact, but it also harms plant roots and beneficial soil microbes. It is not recommended for garden use. Use soapy water or Bt instead.
Putting It All Together
Getting rid of cutworms requires a mix of observation, prevention, and action. Start by identifying the damage and checking your garden at night. Use collars around every new seedling to stop them from cutting stems. Apply beneficial nematodes or Bt if the infestation is widespread. Keep your garden clean and rotate crops to prevent future outbreaks.
Remember that cutworms are a common problem, but they are manageable. With consistent effort, you can protect your plants and enjoy a healthy harvest. Do not wait until your seedlings are gone—take steps today to keep these night-time feeders away.
One final tip: check your garden after heavy rain. Cutworms sometimes come to the surface when the soil is saturated. This is a good time to handpick them. Also, avoid overwatering, as moist soil attracts moths looking for egg-laying sites.
By following the methods in this guide, you can answer the question “how do you get rid of cutworms” with confidence. Your garden will thank you with strong, healthy plants all season long.