Plant family

Kohlrabi belongs to the brassica family, also called the cabbage or cole crops. Its close relatives that share the same pests and diseases include cabbage, broccoli, cauliflower, kale, Brussels sprouts, collards, turnips, rutabaga, radishes, mustard, and arugula.

Why rotate kohlrabi

When kohlrabi or its brassica relatives grow in the same ground year after year, soilborne problems concentrate there, most notably clubroot, which can persist in the soil for many years, along with black rot, fusarium yellows, and blackleg. Pests such as cabbage root maggot, flea beetles, cabbage aphids, and harlequin bugs also settle in and overwinter near a repeated planting. On top of that, this family draws heavily on nitrogen and other nutrients, so growing it repeatedly in one spot steadily depletes the bed.

What to plant after

Kohlrabi does well following legumes such as peas or beans, because those crops fix nitrogen and leave the soil richer for this moderate to heavy feeder. It also grows nicely after alliums like onions and garlic, or after a leguminous cover crop, since none of these share brassica diseases and they help break the pest cycle.

What to avoid

Avoid planting kohlrabi right before or after any other member of the brassica family, including cabbage, broccoli, cauliflower, kale, turnips, radishes, and mustard, since they host the same pests and soilborne diseases like clubroot and black rot. Following one brassica with another simply lets those problems carry over and intensify in the same bed.

Example rotation

A simple four year plan for one bed could run: Year 1 legumes such as peas or bush beans, Year 2 brassicas including kohlrabi, Year 3 fruiting crops like tomatoes or squash, and Year 4 root crops or alliums such as carrots, beets, or onions. After the four years the cycle starts over, which keeps roughly three seasons between brassica plantings in any given bed.

Tips

Keep a simple garden map or notebook each season so you can see where the brassicas grew and wait at least three to four years before returning kohlrabi to the same spot, which is especially important if clubroot has ever appeared. Grouping all your brassicas together in one bed each year makes the whole family easy to rotate as a block, and sowing a legume cover crop in the off season helps rebuild nitrogen for the next planting.

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.