Vegetable Grow Guides
How to Grow Organic Broccoli from Seed
Brassica oleracea var. italica
About Broccoli
Broccoli is a cool-season brassica. Heads form best in steady 60–70°F weather. Heat makes them bolt to flower; hard frost can scar a mature head but seedlings handle light frost.
When to Plant
Start indoors 4–6 weeks before last frost for a spring crop; transplant 2 weeks before last frost. For fall, start 10–12 weeks before first frost. Time plantings to your frost dates, not a calendar month.
How to Plant
Sow ¼–½ inch deep. Transplant 18–24 inches apart, rows 24–36 inches. That is about 0.3–0.4 plants per square foot — 3-inch spacing is far too tight and will not make heads. Firm soil, water in, and mulch. Side-dress with compost when plants are 8 inches tall.
When to Harvest
Cut the central head with 6 inches of stem when buds are tight and dark, before any yellow flowers open. Leave the plant; many varieties send side shoots for weeks.