Plant family

Turnips belong to the brassica family, also called cole crops or the cabbage family. Their close relatives include cabbage, broccoli, cauliflower, kale, collards, Brussels sprouts, radishes, rutabagas, mustard greens, and bok choy. All of these plants share many of the same pests and diseases, so they should be treated as one group when you plan a rotation.

Why rotate turnips

When turnips or other brassicas grow in the same bed repeatedly, clubroot can build up in the soil and cause swollen, distorted roots that stunt the plants. Cabbage root maggots, flea beetles, and diseases like black rot and downy mildew also carry over from season to season in that spot. Because turnips are a root crop, they draw steadily on soil nutrients, and continuous planting can leave the bed depleted of phosphorus and potassium.

What to plant after

Turnips do well following legumes such as peas, beans, or clover, because these crops fix nitrogen and leave the soil enriched for the leafy top growth. They also make a good follow-up to heavy feeders like tomatoes, squash, or corn, since the ground is often cleared and freshened before fall turnips go in. Following a legume cover crop is especially useful, as it improves both fertility and soil structure ahead of the turnip roots.

What to avoid

Avoid planting turnips right before or after any other brassica, including cabbage, broccoli, cauliflower, kale, radishes, rutabagas, and mustard greens, because they share clubroot, cabbage root maggot, and flea beetle problems that compound in the soil. Also steer clear of following one root crop with another closely related root crop in the same family, since this keeps drawing on the same nutrients and hosts the same pests. Give the bed a break from brassicas before returning turnips to it.

Example rotation

A simple four-year plan for one bed could go like this: Year 1, plant peas or beans (legumes) to build nitrogen. Year 2, grow tomatoes or squash (heavy feeders). Year 3, plant turnips along with other brassicas. Year 4, grow onions, lettuce, or carrots, then start the cycle over. This keeps at least three years between turnip plantings in the same spot.

Tips

Keep a simple garden map or notebook each season so you always know where the brassicas grew and can wait at least three years before returning turnips to a bed, which is one of the best defenses against clubroot. Grouping all your brassicas together in one bed each year makes the whole family easy to move as a block, and sowing a legume cover crop between rotations helps rebuild fertility.

General guidance for US home gardens. Adapt to your own crops, soil, and space; your Cooperative Extension office can help with a plan for your area. Page updated Aug 4, 2026.