Overview
Brassica rapa is a cool-season biennial grown as an annual for its swollen root and leaves. Plants form a rosette of lobed, rough-hairy leaves 6–12 inches (15–30 cm) long and reach 12–24 inches (30–60 cm) tall. The root swells at the soil line into a globe or flattened globe 2–4 inches (5–10 cm) across, white with a purple, red, or green crown depending on the cultivar. Roots are ready 40–60 days from sowing, and greens can be cut at 3–4 weeks. In the second year, or after prolonged cold followed by long days in the first, a branched flower stalk 2–3 feet (60–90 cm) tall bears yellow, four-petaled flowers about 0.5 inch (12 mm) across in racemes. Seed pods are slender siliques 1–2 inches (2.5–5 cm) long. Roots turn woody and pungent when growth is checked by heat above 80°F (27°C), and clubroot, flea beetles, and root maggots affect plantings.
Native Range
Native to temperate Europe and western Asia, with turnip types domesticated in Europe and central Asia. Naturalized on disturbed ground and roadsides across temperate North America.Suggested Uses
Grown in vegetable beds in rows 12–18 inches (30–45 cm) apart, in raised beds, and in containers 8–12 inches (20–30 cm) deep. Roots are eaten boiled, roasted, or raw, and leaves are eaten as greens. Also grown as autumn forage and as a cover crop. Roots store 2–4 months at 32–40°F (0–4°C) in high humidity.How to Identify
Appearance
Size & Dimensions
Height1' - 2'
Width/Spread8" - 1'
Bloom Information
Flowers open in April–May of the second year, or earlier in the first year when plants bolt after cold followed by long days. Individual flowers last 2–3 days, and total bloom lasts 3–4 weeks. Bolting in the first year ends root enlargement.
Detailed Descriptions
Foliage Description
GreenGrowing Conditions
Sun Requirements
Requires 6-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Care & Maintenance
Care Guide
Seeds are sown 0.5 inch (1.25 cm) deep in early spring and again in late summer, and seedlings are thinned to 2–4 inches (5–10 cm) apart. Plants grow in full sun to part shade in moist, well-drained loam at pH 6.0–7.5. Irregular watering causes roots to crack, and 1 inch (2.5 cm) of water per week maintains steady growth. Floating row cover excludes flea beetles, and root maggots lay eggs at the base of plants in spring. Clubroot develops in acidic soil below pH 6.0, and a 3-year rotation away from brassicas reduces its spread.Pruning
No pruning is required. Outer leaves are cut 1 inch (2.5 cm) above the crown when harvested for greens. Flower stalks that appear in the first season are cut, though root enlargement stops after bolting.Pruning Schedule
Prune: April
late spring
Container Growing
Suitable for container growing
Minimum container size: 2 gallons
Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
Early spring 4 weeks before the last frost, and late summer 8-10 weeks before the first fall frost
Days to Maturity
40–60 days
Plant Spacing
3 inches