At a glance
Ease of culture: Moderate
Where: All zones
Best climate: Cool season
When: Autumn, winter, spring
Spacing: European cabbages 60-80cm; Chinese cabbage 40-50cm; kale 40-50cm; bok choy 20-30cm
• Cabbages and their friends prefer cool conditions
• Most grow best during autumn, winter and spring, as well as summer in cooler districts, where it is possible to grow them year round.
• Mature plants are more frost-tolerant than seedlings. Time your planting accordingly or provide seedlings with frost protection when necessary.
• The growing season is much shorter in tropical areas, restricted to late autumn to early spring. Heat-tolerant varieties, like sugarloaf and fast-growing Asian greens like bok choy and wombok, are the best options here.
• Traditional European cabbages are slow growing and need a long, cool season to initiate heading. In subtropical areas, plant in April to take advantage of the 4-5 cool months ahead.
Box: Extend your growing season
The sudden arrival of hot weather in spring can spell the end of cabbages in warm areas, causing them to bolt to seed prematurely. Shading crops on hot days will take the edge off the heat and keep your cabbage crops thriving for longer. All you need is a piece of shade cloth draped over a frame of bamboo or tomato stakes.
• Find a spot in full sun with at least 6 hours direct sunlight per day
• Choose a spot with protection from strong wind
• Like all brassicas, cabbages 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.
• Cabbages are an ideal crop to grow immediately following a nitrogen-fixing legume crop, such as peas or beans
• The ideal pH for cabbages is slightly acid to slightly alkaline (6.5-7.5). 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
• Seedlings are readily available from nurseries. However, cabbages are very easy to raise from seed, and this gives you the widest possible selection of varieties.
• Seeds are best sown directly in the soil.
• Rake the soil surface level, and then press the handle of your rake into the soil to create furrows approximately 10mm deep.
• Dribble seed into furrows at approximately half their recommended spacing (see below) and thin out or transplant later.
• Cover seed with about 5mm of sieved compost or coco peat.
• Water in well and keep moist until seeds germinate (6-12 days)
• Thin seedlings: European cabbages 60-80cm; Chinese cabbage 40-50cm; kale 40-50cm; bok choy 20-30cm
Watering, fertilising and care
• Feed and water cabbages regularly or they will sit and sulk.
• Sprinkle a light application of a well-balanced organic fertiliser around plants 3 weeks after planting and once a month for the months following.
• Supplement feeding with a weekly application of fish emulsion and liquid seaweed at half strength
• Mulch the soil around plants to retain moisture and suppress weeds
• Harvest hearting cabbages (including wombok) when the hearts are firm (10-14 weeks). Use a sharp knife to cut and remove the heart deep within the plant. This will encourage secondary heads to form on the existing plant (if the growing season allows).
• Begin harvesting kale as soon as plants are large enough (4-6 weeks). Remove other leaves first by snapping them cleanly from central stem. Leave behind at least 5-10 leaves to allow the plant to continue to grow.
• Asian greens such as bok choy and pak choy can be harvested when 6 weeks old by removing the entire plant (this is when they are most tender), or by removing the older leaves as for kale (above). This will extend the harvest season of plants before they develop flowers and seed (about 12 weeks old).
• Tatsoi (Chinese flat cabbage) can be harvested like kale for up to 6 months during ideal growing conditions.
Box: The wonders of kale
Kale was a very important crop in early European culture, and recently returned to popularity after many years of being widely forgotten. It’s one of the most nutritious of all vegetables and certainly worth growing. Kale leaves can be picked individually as you need them, and you can continue harvesting from one crop for many months. A crop planted in early autumn will continue cropping right up to Christmas in many areas. Kale copes well with temperature extremes – both hot and cold – so it’s possible to grow it year round in some areas.