Root maggots burrow through plants, making them susceptible to disease and in some cases causing them to wilt and die. Root maggots overwinter in the soil as larvae and pupate near the surface of the soil in the spring, using root crops like turnips for sustenance. Preventing root maggots from invading your turnips takes a combination of methods, beginning the season before you even plant the turnips. Knowing these methods will help keep your turnips healthy and safe.
Destroy all leftover plant material after harvest the season before planting your turnips. Any plant material you leave behind will carry the larvae through the winter to the next season.
Till your garden at least two weeks before planting. Weeds can also serve as a host for root maggots. Do not put fertilizer down at this time as the root maggots prefer organically rich soil.
Practice crop rotation. Choose an area as far away as possible from the spot where you had previously had a root maggot infestation to plant this year's turnip crop.
Place a layer of diatomaceous earth around each turnip plant early in the season. Diatomaceous earth is a coarse, sand-like material that prevents the female root maggots from laying eggs around the base of the turnip. Reapply the diatomaceous earth after each rain. You can purchase this product online or at most garden stores.