How to Grow Mustard Greens: 11 Steps (with Pictures)

Before you plant mustard greens, spread 3-6 inches of compost over your planting area, and plant your seeds about 4 weeks before the last frost in winter. Space the seeds about 1/2-inch apart, and once they grow into seedlings and sprout their first leaves, gently unearth them and pull them apart into clumps. Replant the seedlings about 12 inches apart. Keep the soil evenly and consistently watered, and snip off the leaves when they are about 3-6 inches long. For tips from our horticulture reviewer on harvesting mustard seeds, keep reading!