Cutworms are the larvae—or caterpillars—of a number of different night-flying moth species. Living up to their name, these pesky larvae cut down young plants at the soil surface or below when they feed. Although they do not cause damage once they mature into moths, the amount of destruction they make as larvae can be devastating.
Identification: There are many different species of cutworms. They can be spotted, striped or solid in colors of brown/tan to pink, green, gray or black. Some can appear to be dull or glossy. When disturbed, they tend to curl up into a ball. Species include: black, bronzed, dingy, army, spotted and variegated cutworms. Variegated and spotted species can climb up the plants, eating foliage and fruit and flower buds.
Cutworms tend to hide during the day and feed at night, so if you believe you have an infestation, patrol your garden during the late afternoon or early evening through early morning to see if you can spot these irksome larvae in action.
Life cycle: Adult moths can mate/lay eggs from early spring to late fall. Females love weedy areas, and will lay their eggs—sometimes hundreds at a time— around the stems of the plant or on the soil. Once the larvae hatch, they will begin to feed. Young larvae will overwinter, hiding away in soil, bark or grassy areas until spring. They can feed on young plants from early spring to early summer, right during the growing season.
Control: The first step in controlling cutworms is to spot their locations. As I mentioned earlier, check your garden in the late afternoon, evening or at night to try to spot them. They can grow up to two inches in length. In the morning, you can also check your plants for damage to find the locations for which these bothersome pests may reside. You can also dig around the damaged plant in search of the cutworm and remove it. Here are a few other tips to help fend off cutworms:
• Try delaying plant transplantation or planting, if possible, for a few weeks, to try to starve the hungry larvae.
• Remove weeds and plant debris from your yard to try to reduce the sites in which the moths lay their eggs.
• Lightly tilling/plowing your garden can help expose/kill overwintering cutworms and helps remove plant residue.
• When adding transplants, try making collars out of foil, newspaper or cardboard and place them around the transplants. Make sure to bury the collars a few inches beneath the soil and also extend them up the stem a ways to help keep the cutworms from feeding on the plants.
• Another option is to use insecticides, but try to avoid using this treatment if possible. Only use insecticides if the amount of destruction to your garden is grand and the other options just do not seem to be working. Read the labels and try environmentally-friendly brands.
Although cutworms can cause mayhem in our gardens, with the right identification and control, you can keep your plants healthy and thriving.
Quickly –and easily—identify the most common invasive and/or beneficial insects that may be in your garden by reading Good Bug Bad Bug.
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Want to be a little more eco-friendly but you just can’t seem to get rid of pesky insects? Try Garden Guys Garden Neem, an environmentally friendly insecticide and fungicide.
Use an easy-to-follow visual guide to help diagnose what is ailing your plant and find the right cures in What’s Wrong With My Plant? (And How Do I Fix It?).
Learn how to use design strategies and plants to help overcome potential challenges in the Smart Gardening Series: Problem Solving.