Broccoli
Brassica oleracea var. italica
Start broccoli indoors 7 weeks before your last spring frost, then plant out 2 weeks before your last spring frost. Space plants 18 in (46 cm) apart.
Photo: Downtowngal, CC BY-SA 3.0 · source
When to plant
Timed from your frost dates, so it holds wherever you garden. Give yours and every step below becomes a date.
Optimal Indoor Start
From seedRecommended- Start indoors7 weeks before your last spring frost
- Begin hardening off3 weeks before your last spring frost
- Plant out2 weeks before your last spring frost
- First harvestabout 60 days after planting out
Optimal Transplant
From seed- Plant out2 weeks before your last spring frost
- First harvestabout 60 days after planting out
Optimal Fall Indoor Start
From seed- Start indoorsabout 17 weeks before your first fall frost
- Begin hardening offabout 13 weeks before your first fall frost
- Plant outabout 12 weeks before your first fall frost
- First harvestabout 60 days after planting out
Optimal Fall Transplant
From seed- Plant outabout 12 weeks before your first fall frost
- First harvestabout 60 days after planting out
Growing broccoli
- Spacing in the row
- 18 in (46 cm)
- Between rows
- 30 in (76 cm)
- Planting depth
- 1/4 - 1/2 inch
- Sun
- Full Sun
- Soil
- Well-drained, fertile loam with high organic matter. pH 6.0-7.0.
- Germination
- 7-14 days at 65-80°F
- Harvest season
- Spring, Fall
- Mature height
- 18-36 inches
- Life cycle
- Annual
Sow seeds indoors 6-8 weeks before last frost, or direct sow when soil temperature reaches 50°F, 2-4 weeks before last frost. For a fall crop, sow midsummer.
Watering. Maintain consistent soil moisture, providing 1-1.5 inches of water per week, especially during head development. Avoid drought stress to prevent bolting.
Feeding
- Seedlings
- Apply half-strength balanced liquid fertilizer after true leaves emerge.
- Growing
- Utilize a high-nitrogen granular or liquid fertilizer (e.g., 5-1-1 or blood meal equivalent) every 3-4 weeks once established.
- How often
- Every 3-4 weeks
- Note
- Consistent nutrient availability is critical for robust growth and large, dense heads. Supplement with boron if deficiency symptoms appear.
Your broccoli, planned to the day.
Canopy turns these timings into dates from your own frost data, places every plant at its spacing on your garden map, and tracks it all the way to harvest.