Broccoli takes its name from the Italian words piccoli bracci, meaning “little arms.” Broccoli has quite a few close relatives and variations, and these are designated in botany by the use of “cultivar groups.” Kale and collards, Chinese broccoli, cauliflower, cabbage, Brussels sprouts, and kohlrabi all share the Latin name B. oleracea, but belong to different groups within that single species. Broccoli itself has several varieties: The most common you’re likely to see in grocery stores is called Calabrese in the UK, and just “broccoli” here in North America. There are also sprouting broccoli, Romanesco broccoli (technically a cauliflower), raab (or rapini), and purple cauliflower—which is actually a broccoli. Confusion abounds for the beginner gardener, and lingers for the expert!
Start indoors right around the last frost date or later in spring for summer harvest in 2 to 3 months. For fall harvest, start indoors late spring and transplant in July, harvesting just before the first frost date. For overwintering sprouting broccoli in mild winter areas, start indoors late March to mid-April, and harvest the following February to May. Seeds will germinate in 7-10 days. Optimal temperature for germination: 10-30°C (50-85°F).