Heading Broccoli - Start broccoli seed indoors 5-7 weeks before your anticipated planting date. Optimum soil temperature for seed germination is 50-85 degrees. Harden off plants by exposing them to an increasing number of hours outdoors each day 1-2 weeks prior to transplanting time. Set transplants in the garden 2-4 weeks before average last spring frost. Direct seeding is only recommended for areas with a long, cool spring season that will allow full maturity before summer heat sets in. For a fall harvest, plant transplants about 70 days before average first frost. Broccoli can be successfully direct seeded for a fall harvest 90-100 days before average first frost date. Broccoli is vert frost tolerant.
Sprouting Broccoli (Spring Rapini) - Start indoors, or direct seed in the garden 2-4 weeks before average last frost date. Sow again in mid-summer for fall harvest.