Recommended Varieties: Hispi F1
Where to grow:
Cabbage needs a fertile moisture retentive soil with good drainage. The cabbages will remain in the ground through the Winter so in wet areas raised beds are recommended to avoid them standing in waterlogged soil.
Like all cabbages, Spring cabbage is a heavy feeder soil should be enriched with plenty of well rotted manure and garden compost prior to planting. Soil should be improved a couple of months before planting so because Spring cabbage is planted in September or October is is best to feed the soil in Spring and plant a light feeding intermediate crop like garlic or onions.
When to grow:
Normally spring cabbage varieties can be sown during July and August. For all varieties it’s a good idea to make successional sowings allowing you to harvest continually while the leaves are young and tender.
Sowing Spring Cabbage
Like most brassicas Spring Cabbage is best sown in a modular seedling tray as the plants don't like root disturbance. Sow 2 seed per module at 1.5cm deep in an 84 cell plant tray, if 2 seedlings emerge nip out the weaker one with a nail scissors. They will germinate in 5-7 days and be ready to plant out about 4 weeks later. You can read more about sowing in modular trays here.
Spacing is 40cm between plants and 40cm between rows but can be planted at 30 cm spacings for smaller heads or Spring greens (Spring greens are cabbage leaves harvested before the heart is produced).
Make a hole in the soil with a trowel or dibber slightly deeper than the seedling root ball. Plant the seedling up to the level of the first true leaves and push the soil in around the plant with your fingers (The true leaves are the second set of leaves produced after the initial rounded seed leaves), the idea is to get a firm connection between the root ball and surrounding soil. All cabbages require a solid footing so firm down around newly plated seedlings.
Seedling plants can be planted up the the base of the first set of true leaves if the stem has got a little leggy from lack of light at the seedling stage. The true leaves are the second set of leaves produced after the initial rounded seed leaves. A light sprinkle of seaweed/poultry manure around the planting hole will help your broccoli get off to a good start. Water it in well if rain is not likely in 24 hours.
Spring Cabbage belongs in the Brassica section of your rotation plan. Only grow any member of the brassica family in the same spot for the minimum of one in every 3 years, preferably 4.
For more information on crop rotation click here.
Hoe carefully around plants with an oscillating hoe to keep weed free and to invigorate the plant feeding microbial life in the soil. In dry weather, keep cabbage well-watered to prevent bolting or running to seed. A layer of garden compost around the plants will also work wonders as it provides a slow release feed and helps retain moisture.
In Autumn earth up around stems to prevent being rocked about by wind, check periodically over winter for plants loosened by wind or frost.
A liquid feed will also be beneficial when the hearts are forming in Spring and early Summer.
Pests and diseases
See below for the most common symptoms of cabbage pest and disease:
Cabbage Root Fly
Look out for blue tinged leaves which wilt in sunny weather. Recent transplants are most vulnerable and will die, when plants are lifted you will find small white maggots around the roots. Use cabbage collars fixed around the plant stems or cover the crop with protective mesh or fleece.
Cabbage caterpillars are active between may and October and lay clusters of yellow eggs under the leaves. When the eggs hatch the caterpillars will start tucking into your plants so it's easier to check the underside of the leaves periodically (or if you see white butterflies hovering around plants) and brush of eggs. To prevent butterflies laying eggs protect the plants a fine insect mesh.
Leatherjackets & Cutworms
Stems are severed at ground level resulting in the death of seedling plants. Leatherjackets and Cutworms are a similar grey/brown colour and live below the surface of the soil where the emerge from at night. If you find one severed stem search the soil in the vicinity and you are likely to find the culprit. To control use a nematode based natural insecticide.
Stunted growth especially if infected as seedlings. Discoloured leaves which wilt. Roots are a thick distorted mass. Clubroot likes acid soil so adding ground limestone or calcifies seaweed will help prevent it's spread. If discovered avoid planting any member of the brassica family for 7-9 years. Isolated gardens rarely have clubroot, it can only enter through infected transplants or walking in infected soil. Applying good crop rotation practices will also help to keep the disease in check.
These are greenfly and blackfly which will be clearly visible on the leaves and especially tender young shoots. These seriously weaken the plant. Control with an organic fatty acid based pest control spray.
Time from sowing seed to harvest is from 11 to 26 weeks, which can be anything from the end of February to the start of June with April and May being the most common harvesting times.
Harvest the cabbage by cutting the head off close to ground level with sharp knife. Try if you can try to leave the outer leaves on the remaining stem. Often a secondary crop of small heads will re-grow on the stalk for harvesting later.