What a shock! You get up in the morning to tour your vegetable garden, in perfect condition the day before, only to find some of the young plants mowed down, cut off at the base. What could have done it?
The answer is “a cutworm”, the larva of a moth (one of many species of Euxoa). The moth lays its eggs in the soil in the fall or early spring, often in weeds or grasses near the garden. The worm itself (actually a caterpillar) is often greyish and rolls up into a C when it is disturbed.
Cutworms can cause considerable damage to young plants, especially vegetables, but also seedlings of annuals, perennials and others. After it hatches in late spring, the cutworm crawls out of the soil at night and chomps away the base of the plant until it crashes to the ground.
To stop the disaster, you’ll have to do a bit of prospecting. With a flashlight, go out into the garden the next night and look for the culprit (it starts to move to the surface of the soil at dusk): cutworms never go very far and should be in the same area where the plants were cut down the day before. Or, if you prefer working in daylight, dig around in the soil near the fallen plant with a trowel, about 2 inches (5 cm) deep: a cutworm is not hard to find.
Or be proactive and protect the base of your plants and your transplanted seedlings before cutworms attack. Cut the bottom off a few cans, plastic pots or plastic, styrofoam or cardboard cups, thus forming a tube. You can even use the tube from a roll of toilet paper! Place a tube barrier around each seedling, pressing the lower part of the barrier into the soil to a depth of 1 inch (2 cm). With a barrier around the base of the plants’ stem, cutworms, which always act right at soil level, will find nothing to eat and will either die or move elsewhere.