How to grow: Brassicas

Broccoli, cauliflower and Brussels sprouts are all members of the cabbage family, often referred to as 'brassicas". These vegetables are simply delicious, and crammed with vitamins and minerals and other health giving properties. Broccoli and cauliflower are the flower heads of the plant that are harvested just before the flowers open. Brussels sprouts are the tight, swollen leaf buds that look like miniature cabbages forming progressively along the tall central stem of the plant.

Source: Benito Martin

At a glance

Ease of culture: Moderate

Where: All zones (except tropical Brussels sprouts)

Best climate: Cool season

When: Autumn, winter, spring

Spacing: Broccoli and cauliflower 40cm, Brussels sprouts 50-90cm

Harvest: 12-16 weeks

pH: 6.5-7.5

 

Climate

• These are cool- to mild-season crops that can handle quite cold conditions

• All are frost hardy. Brussels sprouts are particularly hardy and will tolerate quite severe frost. This is said to improve the quality of sprouts.

• Broccoli is the most warm-hardy and the best of this group for planting in tropical and subtropical climates.

• Cauliflower and Brussels sprouts will grow in southern subtropical regions, but must be planted in early autumn to benefit from a long cool season

 

Position

• Find a spot in full sun with at least 6 hours direct sunlight per day

• These plants are easily damaged, so choose a spot with protection from strong wind

 

Soil

• Brassicas demand a rich, well-drained soil.

• Dig in plenty of compost and well-rotted manure before planting and incorporate it to a spade’s depth.

• These are heavy feeders so incorporate some fertilisers too – a good handful of blood and bone, and a tight fistful of sulphate of potash per square metre.

• Brassica like a slightly acidic to neutral soil. If your soil is acidic, add some lime at the rate of one handful per square metre.

• Water it in well and let it settle for a week or so before planting

 

Sowing

• Seeds can be sown directly in the soil, but for the most reliable results, sow seeds in small pots first and plant out later.

• The best temperature for seed germination is 10-25°C

• The sewing time varies greatly depending on which brassica you are growing and where you live. Refer to the sowing guide below

• Plant out seedlings when well established – about 4-6 weeks after sewing

• These plants topple over easily in strong wind. Plant seedlings a little deeper to cover the lowest leaves. This will help to stabilise the plants.

• Space broccoli and cauliflower seedlings 40cm apart in rows 60cm apart, and Brussels sprouts 50-90cm apart in rows 90cm apart.