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Broccoli (Calabrese)


Ease of Growing [Scale 1-5] - 3 (Medium)

How Time Consuming

Limited – watering, weeding, feeding & staking.

Recommended Varieties

  • ‘Fiesta’ AGM: Very reliable large tight heads followed by side-shoots, high yielding variety for all periods. Tolerant of summer heat.
  • ‘Kabuki’ AGM: Compact plants suited to small garden or containers. Early variety, especially good for autumn cropping.  Harvest heads when small and tender will encourage side shoots to develop for second cropping.
  • ‘Romanesco’ – Often considered a cauliflower with it’s lime green curds but is actually Italian broccoli. Lovely flavour and looks superb.  Sown Apr-May for a Sep-Oct harvest.

Home Grown Vs Supermarket

Home grown always wins for freshness if you have the growing space.

Best Sites and Soils

All broccoli likes full sun/light shade and a rich soil improved with a generous quantity of organic matter.  Soil needs to be firm with a ph of 6.5-7.5

When to sow

Seeds are generally sown between March and June. Sow two seeds per cell in trays in a greenhouse and outdoors from April. Thin to one plant as soon as the seedlings can be handled. Give liquid fertiliser every week at this stage.   When rootball is well bound together plant out into final growing space adding root boost to encourage strong growth. From April, seeds can be sown in the open where the plants are to grow; sow three seeds, 2cm (¾in) deep, every 30cms (12in) along the row. When seedlings are large enough to be handled, thin out each ‘station’ leaving one healthy seedling behind.  Before lifting the plants, water them well and water well again after transplanting.
Distance between rows - Allow 45cm (18”). Closer spacing will reduce the number of side shoots formed.
Distance between plants - Allow 30cm (1ft) apart.

When to harvest

When broccoli heads are well developed but before the flowers open.

Problems to look for:

Pigeons and caterpillars like to attack the plants, so cover them with netting to stop them getting access. Whitefly is a real problem with Sprouts in the Harrod Kitchen Garden. We now cover ours with fine insect mesh which prevents these pests from taking hold.

We have had clubroot in the distant past in the Kitchen Garden and consequently now plant all our brassicas with cabbage collars around the base to prevent this disease from returning.

Meet the Author: Jo Blackwell
Jo Blackwell

Jo Blackwell is our well-established Horticultural Advisor and the Kitchen Gardener in Stephanie's Victorian style Kitchen Garden. She caught the gardening bug when she bought her first home 21 years ago. Her first greenhouse soon followed and she later gained an allotment.

As well as tending the Harrod Horticultural Gardens, she enjoys maintaining her own vegetable plot at home. She has been a gardener for Harrod Horticultural for over 4 years now and has a wealth of experience in organic vegetable growing, ornamental gardening and in using all Harrod products.


Further Information

Watering / Feeding - As the plants develop make sure they do not go short of water this is essential for the formation of good spears. Mulching will help to conserve water. 


Guide to sowing and planting - Always plant Brassicas out deeply with the bottom leaves touching the soil, by planting deep this will protect the plants from being blown up by the wind (wind rock). 
Calabrese (like all Brassicas) does not like having it’s roots disturbed.
The plants may become top heavy and require staking for support.


Problems to look out for - Brassicas can be prone to a number of pests/diseases:-

Cabbage white butterfly are attracted to Brassicas and will lay eggs on the underside of the leaves, producing caterpillars which will eat holes in the leaves, often decimating the plant overnight.  Use Fleece or butterfly net to protect plants.
Cabbage Root Fly – symptoms include poor growth, blue tinged leaves and wilting.  When the plants are lifted all the fine root hairs will have been eaten and small white maggots are frequently seen near the roots. Cabbage Collars are available to protect against Cabbage Root Fly.
Club Root – causes poor growth, wilting and discoloured leaves.  When the plants are pulled up the roots are swollen with reduced root hairs.  These will need to be destroyed, do not compost to prevent spreading the disease. To overcome this problem grow club root resistant varieties, ensure the soil pH is above 7.5, grow on well drained soil and practice good crop rotation.
Birds can be a problem so net plants when the heads are being produced.
Slugs & Snails – Protect young plants 


How to harvest by type - Cut the florets from the plants using a sharp knife.  Cut the central spear first to encourage side shouts to grow.

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