Finding maggots in your yard can instantly make you feel grimy all over. Just the thought of those squirmy, wormy-looking insects near your home is almost enough to make you want to grab the kids and move away. Maggots in your yard aren't much of a threat to most of your landscape plantings -- or your family -- but they can wreak havoc among your vegetables.
Maggots are basically baby flies. When flies lay eggs, the eggs hatch as maggots. These hungry critters eat their fill before they pupate and turn into adult flies. Some flies, such as the drone fly, munch mostly on rotting food or animal excrement -- these are the type you're likely to see invading your outdoor garbage can, for example. They're nasty, but not much of a danger to your plants. Root maggots, such as those from the Delia fly family, can quickly take over your vegetable garden and eat the roots of plants, especially onions (Allium cepa) and cabbage (Brassica oleracea).
Signs of Maggots
Without the ability to see underground, you often don't know there's a problem until it's too late. After maggots eat most of a plant's root system, the plant starts to wilt or turn yellow. It could be just one of your plants or an entire row of vegetables. To check whether maggots are the problem, dig up one of the plants. The plant might lack roots completely, or there might be just a few stragglers left. If you have root vegetables, the developing vegetable might have holes tunneled through and may have started to rot, rendering it inedible for people.
When you want to get rid of the maggots but don't want to introduce powerful chemical herbicides near where your children play, organic options can help. Cover susceptible vegetables with fabric row covers to let in light and moisture while keeping out the flies. Just make sure the row covers reach the ground and are held down with rocks or landscape staples. This keeps flies from laying eggs near your plants. Try placing sticky traps throughout your garden as well. These catch the adult flies, reducing the number available to mate and lay eggs.
The "ick" factor might demand that you do something to quickly eliminate the maggot problem. Sprinkling a handful of diatomaceous earth around the base of each plant after each rain or watering can help get rid of maggots. Chemical soil drenches, such as those containing chlorpyrifos, can also help. Check the manufacturer's instructions for your specific vegetables, but for a general mixture, combine 1 cup of chlorpyrifos with 1/2 cup of water per plant and pour it around the plant's base. Water it in thoroughly.