Mustard Greens

Mustard greens grow so fast that they can make you feel like you're doing everything right — and then bolt so fast that they make you feel like you did everything wrong. The two things are connected. The same vigor that pushes a plant to full leaf in four weeks is what sends it to seed in the fifth week when temperatures tick upward. Mustard greens require you to pay attention and harvest on time, not when convenient.

Direct sow about four weeks before your last frost. The seeds germinate in three to five days in cool soil and the seedlings are cold-tolerant. Thin to six inches once the plants are a few inches tall; crowded plants compete for resources and bolt sooner. Succession sowing every two weeks from early spring can extend the harvest into late spring, though each successive sowing has a shorter window as the season warms. Fall is often the more satisfying season — sow about six to eight weeks before your first expected fall frost and harvest through October and November.

Mustard greens want reasonably fertile, moist soil. In rich soil with consistent watering, the leaves stay tender and the peppery flavor is lively but not harsh. In dry or poor soil, the leaves become tough and the flavor turns aggressively hot and bitter, particularly in warm weather. A compost-amended bed at planting is usually sufficient; mustard is not a heavy feeder the way broccoli or cabbage is.

Bolting is the dominant failure mode. When temperatures climb above 75 degrees or day length extends past 14 hours, the plant begins its reproductive phase. A central stalk elongates, the leaves become small and misshapen, and the flavor intensifies to the point of unpleasantness. This can happen within a week of ideal conditions. Watch the center of each plant daily in late spring — the moment you see the stalk beginning to push up, harvest the entire plant immediately. Once bolting is underway, the harvest is over.

Baby mustard leaves, harvested at two to three inches, are mild enough for salads. Full-size leaves at six to ten inches have the classic peppery bite that holds up to sautéing, braising, and pickling. Southern Giant Curled and Green Wave are the traditional choices for cooked Southern-style mustard greens. Mizuna is milder, with feathery leaves, and stays usable slightly longer before bolting. Red Giant and Osaka Purple add color to the bed and the plate, and tend to have stronger, more complex flavor.