8 Tips on How to Get Rid of Cutworms Before They Eat Your Seedlings

2024-02-20
8 Tips on How to Get Rid of Cutworms Before They Eat Your Seedlings

For anyone growing seedlings in the garden, knowing how to get rid of cutworms is going to come in handy. Cutworms aren’t as well known as tomato hornworms and cabbage loopers, but these voracious little caterpillars do a lot of damage to vegetable gardens. Unlike hornworms, cutworms are generalist feeders that target a wide range of crops, and they’re particularly problematic for seedlings and young transplants.

When they strike, cutworms bite off seedling stems at the soil line, causing rapid plant wilting and death. However, these tips on how get rid of cutworms will help you protect seedlings through proper garden maintenance and organic treatment methods.

What Are Cutworms?

Cutworm caterpillars are the larvae of several species of moths. Because there are many varieties, they don’t all look the same. Cutworms have smooth, hair-free bodies that can be striped, spotted, or colored in shades of gray, brown, green, black, tan, or pink. Full-sized cutworms are about 2 inches long and have a curious habit of dramatically curling into a C-shape when disturbed.

After pupating, cutworms emerge as adult moths, which are brown to black in color and measure 1 to 1 ½ inches long. Adult moths lay their eggs on plant debris from spring through fall; the cutworm eggs overwinter outdoors in the soil and reemerge in spring. Both adult moths and larval cutworms are primarily nocturnal; however, the adults don’t feed on plants.

Small populations of cutworms don’t do much damage, but a large number of cutworms can wreak havoc on vegetable gardens. These pests aren’t picky about what they eat, and they can damage a wide variety of plants, including:

  • Cabbage and other brassicas
  • Tomatoes and other nightshades
  • Asparagus
  • Beans and peas
  • Lettuce
  • Carrots
  • Celery
  • And sometimes turf grass

Identifying Cutworm Damage

As their name suggests, cutworms feed on plants at the soil line and often “cut” right through tender plant stems and cause plants to topple over. Cutworms also feed on plant roots and sometimes climb and nibble on leaf petioles and growing plant shoots on the upper portion of plants.

The most common signs of cutworm activity include:

  • Transplants and seedlings with damaged stems cut off at the soil line
  • Outdoor seedlings and transplants that wither quickly, even when they’re watered thoroughly
  • Young seedlings that disappear overnight
  • Healthy plant leaves that are clipped off without other signs of damage
  • Holes and cavities bored into tomatoes, potatoes, cauliflowers, and other crops
  • Cutworm frass beneath affected plants

Cutworm activity is most pronounced at the beginning of the season, but some species of cutworms remain active throughout summer and into fall. Cutworm damage is sometimes confused with the damage caused by slugs and snails. However, cutworms don’t leave behind silvery slime trails, and holes caused by cutworms are typically smaller than the damage left by slugs and snails.

Tips to Naturally Prevent Cutworm Damage

Keep cutworm activity in your garden down to a bare minimum with these tips.

1. Keep gardens tidy.

Cutworms can overwinter in old plant debris, so clean up your garden in the fall if you’ve struggled with cutworms during the growing season. Destroy any infected plant matter by burning it or bagging it and throwing it in the trash. When spring arrives, rotate your crops and consider installing floating row covers to prevent cutworm moths from landing on vulnerable veggies and laying their eggs.

2. Handpick cutworms.

One of the best ways to manage an existing cutworm infestation is to handpick cutworms and drop them into a bucket of soapy water. For best results, head out in the evening or after dark with a flashlight and scan around the base of damaged plants for cutworms. If you don’t see cutworms right away, brush your hand against the soil to see if any cutworms move about and curl up into C-shaped balls.

3. Use plant collars.

Plant collars act like a barrier around seedling stems, shielding young plants from cutworms that may be at work in the soil. Typically, plant collars are made of 4-inch-long pieces of cardboard or aluminum foil. They’re partially sunk into the soil to loosely encircle plant stems. Install the collars when you transplant the seedlings into the garden. Remove them later in the season when cutworms are less active and the plants are well-established.

4. Experiment with companion planting.

Companion planting with the right plants is an important tool for organic gardening. Marigolds, for example, are known to repel cutworms, and growing these flowers near vulnerable vegetables can keep your garden pest-free. You may also want to grow flowering herbs like dill, cilantro, or parsley near your vegetables, as herb flowers attract predatory wasps and other insects that feed on cutworms.

5. Attract natural predators.

Predatory insects aren’t the only critters that hunt cutworms; wild birds also love eating cutworms. Installing bird feeders and a bird bath or other water element near your garden will attract a variety of birds that will happily patrol your garden beds and gobble up any insects they find.

6. Delay transplanting.

Cutworms are most active in early spring when they wait patiently in the garden for tender young seedlings to be appear after the long winter. However, if you wait a few weeks to transplant vegetables into your outdoor beds, the cutworms are usually less active, and the plants are less likely to be targeted.

7. Till the soil.

If you struggled with severe infestations of cutworms in the past, a well-timed tilling of the soil may be in order. Tilling gardens in either spring or fall exposes cutworms to the air and makes them easier for birds to spot.

8. Try organic pesticides.

Cutworms can usually be managed with handpicking and garden maintenance, but if you need to resort to pesticides, choose organic options that are less damaging to pollinators. Thuricide BT is an organic pesticide you can spray on affected plant leaves to kill off pest caterpillars, and sprinkling diatomaceous earth around the soil line prevents cutworms from crawling onto young plants. Even these organic products can harm pollinators if they’re improperly applied, and they should never be used directly on flowers. Always follow label directions for any pesticide.

Frequently Asked Questions

  • Do coffee grounds deter cutworms?

    Many gardeners swear by using coffee grounds as cutworm deterrents, but there is no current scientific evidence to support the use of this garden remedy.

  • Where do cutworms hide during the day?

    Cutworms are most active at night and hide in leaf litter and soil during the day. Running your hand across the soil beneath infected plants makes it much easier to spot stealthy cutworms while they’re hiding.

  • Are cutworms and armyworms the same thing?

    No. Armyworms and cutworms look similar, but they are different creatures. Cutworms tend to have more solitary feeding habits, while armyworms often feed in groups.

Related Article

8 Begonia Houseplant Care Tips to Keep Your Plants Thriving

8 Begonia Houseplant Care Tips to Keep Your Plants Thriving

Find out how to care for begonia houseplants with these tips on the best types to grow, lighting, watering, fertilizer, and more.
How to Plant and Grow Peperomia

How to Plant and Grow Peperomia

Peperomia is grown for its foliage and is one of the easiest to grow in your home—even the bathroom!
How to Plant, Grow, and Care for Korean Rock Ferns

How to Plant, Grow, and Care for Korean Rock Ferns

Learn how to grow and care for Korean rock ferns indoors and out in the garden. Get essential tips on light, watering, fertilizing, and more.
7 Best Perennial Flowers That Bloom in Winter

7 Best Perennial Flowers That Bloom in Winter

Add these winter-blooming perennials to your garden to brighten the cold weather months.
How to Harvest Black Walnuts and Enjoy Their Delicious Flavor

How to Harvest Black Walnuts and Enjoy Their Delicious Flavor

Find out when and how to harvest black walnuts from your yard or local forest. Plus, get must-know tips for cracking the super tough shells.
This Easy-Care Butterfly Garden Plan Will Attract Tons of Pollinators

This Easy-Care Butterfly Garden Plan Will Attract Tons of Pollinators

Use this gorgeous butterfly garden plan to create a bed of flowers that will bring beautiful and beneficial insects to your garden.
22 Beautiful Garden Plans for Attracting Birds and Butterflies

22 Beautiful Garden Plans for Attracting Birds and Butterflies

Create a butterfly- and bird-friendly landscape with these garden plans. Each design includes a mix of plants that can provide nectar, seeds, and shelter to wildlife. Add a water source to further enhance the habitat.
16 Pretty and Simple Combinations of Window Box Flowers for Shade

16 Pretty and Simple Combinations of Window Box Flowers for Shade

Here are 16 beautiful and easy-care combinations of window box flowers for shade to add color wherever you need it.
How to Grow Vegetables in Containers for a Plentiful Garden

How to Grow Vegetables in Containers for a Plentiful Garden

Pick the right plants and you can grow a fair amount of food in just a few large pots! Here’s how.
How to Harvest Lettuce: 6 Tips for Picking Leaves at Their Peak

How to Harvest Lettuce: 6 Tips for Picking Leaves at Their Peak

Learn how to harvest lettuce properly with these simple techniques so you can enjoy garden-fresh greens at their peak.
How to Use Fertilizer for Plants According to Experts

How to Use Fertilizer for Plants According to Experts

Get expert tips on fertilizing plants, including the best formulation for both houseplants and garden plants, as well as how frequently you should feed them.
The Best Time to Add Fertilizer to Your Lawn Before Winter

The Best Time to Add Fertilizer to Your Lawn Before Winter

Cultivate a happy, healthy lawn all year long with a nutrient boost before freezing weather occurs.
What Is Loam Soil and How Can You Create It in Your Garden?

What Is Loam Soil and How Can You Create It in Your Garden?

Loam soil is often mentioned as best for plants. But what is loam soil exactly? Here's what to know about this ideal soil type.
How Often—and How Long—You Should Water Your Grass

How Often—and How Long—You Should Water Your Grass

Whether you water manually or you have an underground sprinkler system, follow our tips for how long and how often to water your grass to keep from overwatering your lawn.
8 Tips on How to Get Rid of Cutworms Before They Eat Your Seedlings

8 Tips on How to Get Rid of Cutworms Before They Eat Your Seedlings

To protect young seedlings and transplants, find out how to get rid of cutworms in your garden with these easy-to-follow organic pest control tips.
8 Small Front Yard Landscaping Ideas to Make the Most of Your Space

8 Small Front Yard Landscaping Ideas to Make the Most of Your Space

Create a beautiful and welcoming small front yard with these tips and ideas.
How to Plant and Grow Papyrus

How to Plant and Grow Papyrus

Find essential tips on growing papyrus, an easy-care water plant that can remain outdoors year-round in a warm climate.
Garden Privacy Ideas that Incorporate Landscaping and Hardscaping

Garden Privacy Ideas that Incorporate Landscaping and Hardscaping

Check out these garden privacy ideas that include landscaping and hardscaping for creating a beautiful and private oasis in your yard.
Super Plants for Kentucky Landscapes

Super Plants for Kentucky Landscapes

Beautiful landscapes start with outstanding plants, and these award-winners are perfectly suited to Kentucky gardens.
15 Super Plants for Texas Landscapes

15 Super Plants for Texas Landscapes

These plants are superstars in Texas gardens and landscapes. Experts recommend them for their ability to thrive in south-central climates.