Cabbage maggots, harlequin beetles, flea beetles and other pests infest radishes, eating holes in their leaves, stems and roots. Here are some ways to prevent these pests.
1. Remove plant debris from areas where radishes were growing, at the end of the growing season.
2. Dig up weeds or ground cover growing near radishes with a garden fork or trowel in the spring, and continue to remove weeds as they appear throughout the year.
3. Grow radish plants on a new site every year for at least three years.