Heirloom cauliflower is a bit more difficult to grow where summers are hot because the plants prefer cool temperatures (60-75°). For best success, grow it so that the heads are forming in late summer and early fall when temperatures are cooler. Start seeds indoor or outdoors 5/15-6/15 (we recommend starting seeds in containers where they can be tended and protected better). Transplate outside 6/15-7/15. Space plants 18" apart in rows 24" apart. Cauliflower plants need lots of compost & organic fertilizer. Water regularly. Protect plants from slugs (use Sluggo), rabbits, groundhogs, deer and cabbage worms (use BT).
Harvest heads when still compact and tight. Use a knife to cut. Leaves are also edible but may be tough.
Cauliflower is difficult to save seed from. It is in the Brassica family so it is insect pollinated and cross-pollinated. It also suffers from inbreeding depression if you don’t save seeds from enough plants. Cauliflower prefers cool weather during flowering which is difficult in Midwest summer heat. Cauliflower will cross with any Brassica oleracea that are flowering at the same time (kale, collards, cabbage, broccoli, brussels sprouts, kohlrabi, cauliflower). Isolation distance: ½ mile. Minimum population size: 10-50 plants. To harvest seed, allow plants to flower and collect seed when mature.
