Growing from Seed 

Choose a site that has good drainage and air circulation, gets full sun or light shade, and where broccoli, cauliflower or other members of the Brassica genus have not grown for at least four years. And, because broccoli grows about three feet tall, choose a site where the plants won't shade other crops.Plant seeds in soil to which you've added plenty of compost or well-rotted manure. The plants perform best in soil with a neutral pH of 7.0, but they'll do fine with anything between 6.2 and 7.2. 

Sow broccoli seeds directly into the garden a month or two before the last frost in cool climates or in early spring in warmer regions. 

Get a jump on the growing season by starting seeds indoors six to eight weeks before the last frost. Put hardened-off seedlings into the ground about two weeks before the last frost, setting them into the soil up to their first true leaves and about 18 inches apart.