Why Grow It?
Why not? It’s relatively handy to grow and can be succession sown so that you can crop almost all summer and autumn long. It’s important to mention that the standard “broccoli” that we buy in shops with the big green tightly-packed head is actually called calabrese. It is traditionally harvested in summer and autumn. “Sprouting broccoli” is a different vegetable – it produces small florets in purple or white varieties and is traditionally harvested in winter and spring.
Sow three or four plants indoors in late March, the same in early May and again in early June. Sow two seeds per module in a module tray about 2cm deep. If both seeds germinate, remove the weaker one. The seedlings will be ready to transplant in a month. You can sow a couple of plants in early March indoors for an early polytunnel/greenhouse crop.
Include calabrese and sprouting broccoli in your brassica rotation – do not grow them anywhere that you have grown any member of the cabbage family the previous year. Plant them in soil that has been manured well the previous autumn. Space plants 15cm apart in rows that are 30cm apart. Water well and frequently and keep the base of the plants weed free. If the plant dries out you will get a low yield. An occasional liquid feed made from nettles will help give the plants the nitrogen they need.
It will be ready to harvest 3-4 months after sowing so you should get your first calabrese crop in early July. Start harvesting by cutting the central head before any of its flowers open and while it is 10cm diameter or less. Once this is removed, smaller side shoots will develop. The more you cut, the more it will produce. It should go on cropping for 4-6 weeks.
Calabrese is susceptible to the same issues as cabbage and other brassicas.