Broccoli, the darling of nutritionists, loves steady, cool weather. That’s why most commercial production takes place along the central California coast, where Pacific Ocean fogs and breezes keep the fields cool enough to grow it year-round.
Although the entire broccoli plant is edible, we grow it mainly for its tightly packed clusters of green flower buds. Historically, broccoli plants had multiple long florets in a loose bunch. In recent decades, varieties bred for a single, large flower head have come to dominate in the United States, though older, looser types—called sprouting broccoli—are still popular in Europe. Many big-headed varieties will keep producing smaller side florets for weeks if left in the ground after the main head is harvested.
Broccoli is relatively sensitive to both summer heat and autumn frosts, so choose varieties and planting dates carefully. Days and nights must be cool for heads to form. For spring crops, set out transplants when they have two to four leaves about 2 weeks before you expect your last frost; for fall crops, set the transplants out in late July or early August.
A plant often called purple cauliflower is actually a long-season type of broccoli that can be planted in early spring for fall harvest or in fall to overwinter for spring harvest in USDA Plant Hardiness Zones 6, 7, and 8. If it is harvested before frost, it tastes more like broccoli; if harvested after frost, it evokes cauliflower. Sadly, it loses its purple tint when cooked.
Romanesco broccoli, also called Romanesco cauliflower or broccoflower, has a lime green, alien-looking flower head with a swirl of pointy protuberances. It requires lots of space and a long growing season but has an interesting nutty flavor when cooked. And broccoli raab? Different species.
Recommended Broccoli Varieties