Tender little turnip greens (Brassica rapa var. rapifera) make salads pop with their mustardlike flavor, and these fast-growing greens pretty much take care of themselves as long as the growing season is right. Though technically a biennial hardy in U.S. Department of Agriculture plant hardiness zones 3 through 10, turnips are most commonly grown as an annual, cool-season vegetable crop.
Sun and Soil
Turnip greens like lots of sun, good drainage and lots of water. Ideally, find a spot that gets at least six hours of direct sun a day with loamy or sandy soil. Space the seedlings 2 to 4 inches apart. Since you'll be harvesting the tender greens, rather than the turnips themselves, you can grow the plants close together. For a turnip harvest, you'd go with a spacing of about 6 inches between plants.
Water turnip greens once a week during dry weather. The greens need about 1 inch of water per week, but if you have fast-draining soil that dries out quickly, you may need more water. Feel the soil, and if it's dry half an inch down, add water. During hot days, the greens may need watering more frequently than once a week.
Turnip greens don't require a lot of extra nutrients during the growing season. Ideally, mix 1 cup of 10-20-10 fertilizer for each 10-foot row into the soil before you plant. You can replace the fertilizer with compost before planting. Use seasoned compost and spread it 1 to 3 inches deep. Mix it into the soil 3 to 4 inches deep before planting.
Growing turnip greens doesn't take much time -- some are ready in as few as 28 days and most within 40 days of planting -- but they need cool weather to grow well. In cold winter climates, grow turnip greens in the spring and fall. If winters are cool and damp and mostly frost-free with hot summers, grow turnip greens in the winter garden. You can spread out the harvest by planting two or three separate plantings 10 days apart.
Using Turnip Greens
Turnip greens are ready to eat as soon as they get 6 inches tall. At this early stage they go well in salads and are tender enough to eat raw. As the plants mature, the leaves get gradually tougher and are better consumed after being sauteed or stewed. Treat mature turnip greens like you would other leafy green vegetables, such as kale (Brassica oleracea [Acephala group]), an annual hardy in USDA zones 2 through 11.