Cutworms

Cutworms are the larvae of several species of nocturnal moth. They live under the soil, in high grass and weeds, or under piles of debris. Their eggs, which can be expected to hatch in the fall, can also be found in similar, enclosed or shrouded locations. They come out to feed at night and will eat the first portion of the plant they encounter, which is generally the stem. They do the majority of their damage when they first emerge from hibernation, which is at the beginning of the growing season. Often mistaken for grubs, they are actually a type of caterpillar.

Important Notes:

  • Eggs often found in high grass and weeds
  • Hide during the day under litter and soil; come out at night to feed.
  • Do the majority of damage at the beginning of the growing season.

Dealing with a Cutworm Problem

Cutworms received their name because of how they feed. Since they eat the plant beginning at the stem, they “cut” down the plan from its base. They can be found most easily at dusk when they first emerge to feed. They also prefer cloudy days over sunny ones.

Cutworms may be up to two inches in length and can range in color from grey to pink, to green and black. They are often spotted in color as well. They will generally be found curled up when not moving about. Adult cutworms are dark-winged moths – usually 1 ½ inches in length with brown or grey dark, possibly spotted wings. Female moths will lay eggs in the dry soil.

Cutworms eat the roots and bottom-most vegetation of almost all plants. They usually eat the foliage and roots of young plants, destroying them from the beneath the soil. Usually, the entire plant will be destroyed, often very quickly.

Types of Problems Caused:

  • Destroys vegetation from underneath the soil. Eats – or “cuts” – roots, leaves and stem at the base of the plant.

Getting Rid of Cutworms

Thankfully, we don’t have to resort to accepting these nocturnal moth larvae plant-cutters in our gardens! There are a few different methods for cutworm removal, so feel free to take your pick.

The most straightforward solution is plow your garden (but remember, here on the farm we promote no-till practices to maintain the life on our soil) as minimally as possible, which will destroy the cutworms’ homes. You should also mow any grass where the worms may be hiding, and clean up litter or debris piles.

An easy home DIY method is to make collars for your plants. These can be made from paper towel or toilet paper roll insets, which you have cut into two or three-inch tall rings. Cut each ring along one side so that you can slip it around your plant’s base. Voila! Now the cutworms will not be able to crawl over this barrier to chow down!

A second simple home option is to re-use some of those coffee grounds or eggshells you have been saving. (You have been keeping those, right?) The scent and texture of both will repel the cutworms.

If you decide to use any forms of insecticide, apply in the afternoon, close to dusk, for the most effectiveness. We recommend a natural pesticide if you choose to go this route. Bacillus thuringiensis is one option that has proven effective for many growers, but beware that it is harmful to butterflies, which are beneficial and necessary to pollination. A better option could be proper mulching, especially with oak leaves.

Cutworms also have multiple natural predators. Fireflies can be a fun addition to your garden, and if you have kids or pets, these are always a fun summertime treat to watch with them in the evening. Several species of bird also consider the cutworm delicious. Placing feeders and bird baths around your property will help to encourage our flying friends to stick around and find a snack. Finally, skunks will also dig up cutworms. We suggest if you see a skunk in your yard, just leave it alone. You’ll be very glad you did.

Our final suggestion for cutworm removal is to invest in beneficial nematodes or Diatomaceous Earth. These can be purchased and added to your garden and will help to prevent many pests, including cutworms. We really cannot say enough about beneficial nematodes, or DE.

Methods for Removal:

  • At end of growing season, plow the garden, effectively destroying their homes.
    • Also, mow any tall grass
  • Make DIY collars for plants
  • Sprinkle coffee grounds or eggshells around the garden
  • Use organic insecticide close to dusk
  • Mulch with oak leaves
  • Encourage natural predators, such as:
    • Fireflies are a natural predator and fun to watch
    • Skunks will dig up cutworms and eat the larvae.
    • Birds including blue jays, blackbirds, wren, and sparrows will eat cutworms. Place birdbaths and bird feeders around your home and garden to encourage their presence.
  • Beneficial nematodes or Diatomaceous Earth (affiliate links) will also destroy cutworms.

Cutworms are probably one of the more disgusting pests to deal with in the garden, and we feel your frustration. None of the insects or critters we battle are fun, but these guys are just downright gross. Hang in there, the cutworms too will not defeat us. Every pest has a solution. Reach out to us anytime if you need additional help. We are here for you.

Happy Gardening!