Botanical Name: Brassica rapa
Days to Maturity: 30–40 days
Native: Probably Eurasia
Hardiness: Frost-tolerant biennial, grown as an annual; will withstand light frost.
Plant Dimensions: 2"–5" diameter roots
Variety Information: 'Market Express' is a white, Japanese salad turnip with dark green, smooth leaf tops, known for being quick to harvest and well-suited for eating fresh as well as cooked.
When to Sow Outside: RECOMMENDED. 2 to 4 weeks before your average last frost date, and when soil temperatures reach 50°F, ideally 65°–80°F. Successive Sowings: Every 2 weeks up to 8 to 10 weeks before your average first fall frost date. Mild Climates: Sow in fall for cool–season harvest.
When to Start Inside: Not recommended; roots sensitive to disturbance.
Days to Emerge: 5–10 days
Seed Depth: ¼"
Seed Spacing: A group of 3 seeds every 4"–6"
Row Spacing: 18"
Thinning: Thin to 1 every 4"–6"
Harvesting: For the most tender turnip, harvest when roots are no larger than 5" in diameter; however, a 3" root will still be of quite good quality. If allowed to grow larger, up to 6", the quality will not be the best for raw use, but will be fine for cooking. If sown for baby greens, harvest greens at 2"–4" tall. Harvesting no more than 25% of the plant's leaves at a time will not affect the plant's ability to produce large roots.