Turnip Growing Information Brassica rapa Direct Seed: As soon as soil can be worked when soil temperature is 55-75° F. Can be grown in tunnel or greenhouse to extend the season. Spacing: Sow 1-2" apart for salad turnips or 2-4” apart for storage turnips in rows that are 12-18" apart, at ¼-½" depth. Growth needs: Prefer cool-season growing in well-drained soil. Tolerant of mild frosts. Salad turnips grow well in warm weather when harvested promptly. Cover with floating row cover after seeding to alleviate pest pressure. Harvest: When of desired size. Storage: For roots with greens, store at 32° F with 95% relative humidity for 10 days and up to two weeks. Topped turnips can store in these conditions for 4-6 months.