How to grow calabrese

A popular and tasty crop, calabrese produces large domed green heads up to 15cm (6in) across, for harvesting in summer and autumn. Growing calabrese yourself means you can enjoy it freshly picked, when its mild flavour and nutritional benefits are at their peak.

Calabrese forms a large green domed head, often sold as ‘broccoli’ in supermarkets

• Calabrese plants produce a large central green head of tightly packed buds, ready to harvest from mid-summer to mid-autumn (this is confusingly called broccoli in supermarkets and recipes) 

• Broccoli plants (also known as sprouting broccoli) produce much smaller clusters of purple or white buds on the tips of leafy stems. For more on this crop, see our guide to growing broccoli

Calabrese is usually sown in spring, either indoors or outside, and is ready to harvest in three or four months, from July to October, depending on the variety and sowing time. It’s a member of the brassica or cabbage family, so should be grown alongside its relatives in crop rotations and should be protected from brassica-eating insects and pigeons – see Common problems, below.

Plants grow up to 60cm (2ft) tall and wide, forming a large central green head, which is a cluster of tightly packed flower buds. This is ready to harvest when large and firm but still tightly in bud. After cutting the main head, further smaller heads form on side-shoots, extending the harvest for up to eight weeks.

Delicious and versatile, calabrese is best lightly steamed or stir-fried and can be used in all kinds of dishes. It’s particularly popular in Italian cuisine and is named after Calabria in southern Italy. Often hailed as a superfood, calabrese is rich in vitamins and antioxidants.

Calabrese prefers firm, fertile, well-drained soil in a sheltered sunny or lightly shaded spot. If possible, choose and prepare your growing site in advance: 

• The previous autumn, dig in two bucketfuls of well-rotted manure or garden compost per square metre/yard, to allow the ground time to settle over winter. If done closer to planting time, firm the soil really well by treading it down, shuffling back and forth over it, then rake it smooth

• If your soil is very acidic, apply lime the previous winter to raise the pH and deter club root disease. Calabrese prefers soil with a pH of at least 6.8

• If your soil is poor, you could rake in a high potassium general fertiliser, such as Vitax Q4. Use one and a half handfuls per square metre/yard – or three handfuls if no manure or garden compost has been added

Calabrese seeds are usually sown between February and June – indoors from late winter into mid-spring, then outdoors from mid-spring to early summer. If you sow several small batches a few weeks apart, you can spread out your harvests and avoid gluts. Calabrese should be grown in the same bed as its other cabbage relatives in crop rotations, to reduce any potential build-up of problems in the soil.

Calabrese is a fast-growing brassica and needs little maintenance apart from weeding regularly, watering in dry spells and ongoing protection from pigeons and certain insects.

Calabrese is harvested in late summer and autumn. The main head is ready to cut when 10–15cm (4–6in) across, well formed but still in bud, before the flowers begin to open. Harvest promptly once ready, as the flowers can open quickly, especially in warm weather.

After you harvest the main head, further small heads will develop on side-shoots, which can be picked regularly over the following weeks. The young, tender leaves can also be eaten. Check plants every few days to ensure you harvest the new heads before the flowers open. Regular harvesting encourages plants to produce further small heads, extending the cropping season for up to a couple of months.

Cut the main head when still tightly in bud, then smaller ones will form on side-shoots

Calabrese usually grows and crops well. But it may bolt in hot weather, meaning it starts to flower prematurely, before plants reach full size, leading to a smaller crop. Harvest these early clusters of buds as soon as you see them forming, before they rapidly open into flowers. Choose a bolt-resistant variety in warmer regions.

Calabrese is also vulnerable to several diseases that affect brassicas, and can be damaged by pigeons and certain insects – see Common problems, below for more details on how to deter or prevent them.