Broccoli planting guide
When to start broccoli seeds
For a spring transplant, start broccoli about five weeks before the outdoor planting date: roughly four weeks of seedling growth followed by about one week of gradual hardening.
Spring lead time
About 5 weeks
Allow about four weeks indoors and one week to harden.
Calculator scope
Spring transplants
Fall broccoli follows a separate local schedule.
Rotation interval
4 years
Avoid planting after related cabbage-family crops.
After main harvest
Watch for side shoots
Smaller shoots can provide another harvest.
Seed-starting calculator
Find when to start seeds indoors
We count backward from the outdoor planting date using university timing guidance.
Seedling stage
Begin hardening after about four weeks
The crop-specific source says plants should have four or five true leaves after about four weeks. Reduce watering and gradually expose them to more sun and wind over the next week.
Source decision
Why the calculator no longer says 10-11 weeks
The general indoor-seed table lists broccoli at 10-11 weeks, but the newer crop-specific guide describes about five weeks through hardening. This site uses the specific crop process and records the conflict.
Plan the bed as well as the date
Rotate cabbage relatives
Do not use a bed that grew cabbage, cauliflower, broccoli, Brussels sprouts, collards, kale, mustard, turnip or rutabaga during the past four years.
Protect young plants
A securely anchored row cover can protect new transplants from wind and insects. Choose material suitable for current temperatures.
Keep harvesting
After cutting the main head, check for smaller side shoots instead of removing the plant immediately.
Fall broccoli needs local timing
The source gives July examples for Minnesota. This page does not reuse those dates nationwide. A fall crop must be planned from local summer heat, expected cold weather and the variety's maturity time.
A practical next step
Plan broccoli with your local season
Cool-season crops may grow before the last spring frost or after summer heat fades. Use crop-specific soil and temperature guidance too.
- 1. Local dates
Find spring and fall frost dates
See historical 32°F freeze estimates and the matched NOAA station for your ZIP Code.
- 2. Season length
Estimate the frost-date growing window
Compare cautious, middle and less-cautious spring/fall date pairs.
- 3. Seed schedule
Count backward for indoor seed starting
Choose a suitable outdoor date for broccoli, then use the reviewed crop-specific lead time to build a seed schedule.