Kohlrabi was hybridized in Europe sometime before the 1500s, a cultivar of wild cabbage selected for its curious swollen stem rather than its leaves or roots. The name means cabbage turnip in German, though it is neither: the edible globe is not a root but the thickened base of the stem itself, sitting just above the soil surface with a loose arrangement of leaves growing from it in all directions. Plants stay compact at 6 inches to a foot tall, shallow-rooted and grateful for consistent moisture and a layer of mulch to hold it.

In North Carolina, kohlrabi is best planted 1 to 2 weeks before the last frost in spring, or in midsummer for a fall and early winter harvest. It tolerates frost but not a hard freeze. The edible portion comes in yellow, white, or red-purple skin tones and should be taken when the rounded area is 2 to 3 inches across — at that size it is tender and sweet, with a clean flavor somewhere between broccoli stem and apple. Left too long, it becomes tough and fibrous, a lesson in the virtue of attentiveness. It can be eaten raw, roasted, or folded into slaws, and makes an unexpectedly handsome edging plant in kitchen garden borders.