Broccoli & Calabrese

Why Grow Broccoli or Calabrese?

A member of the cabbage family, the word broccoli is the plural of the Italian word broccolo, which refers to the flowering head of the cabbage. It originated in the 6th century BC by careful breeding by the Romans in Northern Mediterranean countries, in particular in Calibria in Southern Italy – hence Calibrese.

Today there are 2 main varieties; calabrese broccoli, which has a large solid head of green flower buds that are 10-20cms across, with thick stems and sprouting broccoli, which can be green, white or purple and have a large number of small heads on many thin stalks.

All varieties are rich in vitamin C and are reputed to have anti-carcinogenic properties, but both of these can greatly reduced if the vegetable is boiled, so steaming is preferable. It is also often eaten raw.

Quick Facts
Botanical Name : Brassica oleracea – Italica group
Sowing Time : Broccoli – April to May
Calabrese – April to Early July
Harvest Time : Broccoli
Early Vars. – January to March
Late Vars. – March to May
Calabrese – August to November
Hardiness : Broccoli – Hardy
Calabrese – Not Hardy
Position : Full Sun, Sheltered from strong winds
Soil Type : Firm and rich organic matter.
Average Plant Height : 60-90cm / 2-3ft
Spacing : Broccoli – 60-75cm / 2-2 1/2ft
Calabrese – 30-45cm / 1-1 1/2ft
Spread : 50cm / 20in
Soil and Preparation

Broccoli is a cool-season crop, and will tolerate some frost. As it will occupy the site until the next season, it is vital to start with a soil that is rich in organic matter, moisture retentive and has medium nitrogen levels. As with other brassicas, broccoli requires firm soil to prevent the plants from falling over.

Choose a site that receives reasonable sunshine and deeply dig over in the autumn, incorporating a good amount of well-rotted manure or garden compost. Allow the soil enough time to consolidate and become firm before planting out. Broccoli does not perform very well in acidic soils so lime if necessary in the winter. Apply a general fertilizer in the spring but do not fork over the soil again before planting.

Seeds and Sowing

Broccoli needs to be started off in a seed bed and transplanted to its final position when it is about 7cm / 3in tall. Seeds should be sown 1-2cm / 1/2in deep into your seed bed during April and May, space them 7cm / 3in apart, leaving 15cm / 6in between rows.[/vc_column_text][/vc_column_inner][/vc_row_inner][vc_column_text]Water your seedlings and the row they will be moved to the day before you transplant them. Lift the seedlings from the seed bed carefully, retaining as much soil around their roots as possible. Using a dibber, make holes in their permeant bed at 30cm / 12in intervals for calabrese broccoli or 45cm / 18in for sprouting broccoli. The seedlings should be planted about 2cm / 1in deeper than they were in the seed bed, to fill the holes use your dibber, inserting it into the bed about 5cm / 2in from the hole and then push it towards the seedling, then fill the dibber hole with loose soil. To check you seedling is planted firmly you can pull on one of the leaves, the leaf should tear before the plant is uprooted.

Once you have finished planting your seedlings give them a good watering, if it is warm and dry you may need to keep them watered until they have established.

Caring for your Crop

Keep your crop weed free with regular hoeing, keep moist through dry spells and feed occasionally with a liquid feed. Young plants may need protection from birds and pigeons can cause troubles as winter approaches, netting is the best way to solve bird problems.

As winter approaches draw soil up around the stems of your broccoli and gently firm it in place. If you are in a particularly windy location staking maybe required.


Most modern calabrese are harvested once the central head has formed but before any flower buds open. Smaller secondary spears may form later.

Broccoli is ready to harvest when the spears are well formed but before any flower buds open. Cut off the centre spear first, the plant will usually continue to produce smaller spears which can be harvested when they are ready.

Production should continue for about six weeks as long as you do not harvest all spears at once or let it flower.