Cabbages: Planting season, Harvesting and Pests

Cabbages are of different types and they are classified based on the season of harvesting: spring, summer, autumn, and winter. Spring and Summer cabbages, which are either round or pointed, are smaller and are usually eaten straight after picking. Autumn and winter types have denser heads, are hardier and so can be left in the ground for longer, and can be stored.

Varieties include Savoy cabbages, with crinkly leaves; white Dutch cabbages; red cabbages, which come in summer and autumn varieties; and spring greens, which are either loose leaved cultivars or spring cabbages harvested before heads have formed.

Where to plant Cabbages

Cabbages don’t mind full sun or partial shade, but they do like a fertile soil that will retain moisture and is slightly alkaline – a pH of at least 6.8.

Most importantly, the earth must be firm. Bear in mind that the roots and stems have to support heads that may grow very heavy indeed. Light, sandy soils can be improved by adding either compost or manure during the previous season.

Crop rotation is important. Avoid planting cabbages where you have grown them in the last three years.

When to plant Cabbages

For the continuous harvest, sow cabbages of different types successively through the year. Start undercover at the beginning of spring for an early harvest of summer cabbages, and sow in the late spring and summer for autumn and winter harvesting. You can even sow in mid to late summer for a crop of spring cabbages the following year.

SPRING CABBAGE
SEASON	SPRING	SUMMER	AUTUMN	WINTER
Sow		YES
Transplant			YES
Harvest	YES

SUMMER/AUTUMN CABBAGE
SEASON	SPRING	SUMMER	AUTUMN	WINTER
Sow	YES	YES
Transplant		YES
Harvest		YES	YES

WINTER CABBAGE
SEASON	SPRING	SUMMER	AUTUMN	WINTER
Sow	YES	YES
Transplant		YES
Harvest				YES

RED CABBAGE
SEASON	SPRING	SUMMER	AUTUMN	WINTER
Sow	YES
Transplant	YES	YES
Harvest			YES

How to grow Cabbages from seeds?

It’s best to sow all cabbage seeds in trays, pots or modules- or in a seedbed. Then transplant them to their final position once they are established. Sow thinly and cover with potting or seed compost to a depth of about 2cm(3/4 inch).

Transplanting Cabbage seedlings

Seedlings are ready to transplant when they have about four true leaves. If they have been grown indoors or undercover, harden them off first. After planting, you may want to mulch around to deter cabbage root fly.

1. If you are transplanting from a seedbed, water they plants before lifting. Hold seedlings by their leaves to avoid damaging the roots, and keep seedlings damp in a water-filled trench or a bucket to stop them wilting.
2. Make planting holes 15cm(6inch) deep about 45cm(18inch) apart in shallow drills. Water the holes before carefully lowering the seedlings in, then gently firm the soil around them.

How often should you water Cabbages?

Keep seedlings weed-free and water them regularly. Daily at first in dry weather, then once or twice a week if there is any danger of them drying out. Earth up the stems to support them as the plants grow, and cut off and remove any dead outer leaves.

Harvesting Cabbages

Spring or early summer cabbages can be harvested as “Spring greens” once the young leaves appear, but before they form hearts. Otherwise, leave them until they have “hearted up” and are solid all the way through. Cut off the heads with a sharp knife, and use them immediately.

Autumn and winter cabbages can be harvested later, then stored on shelves or in nets for a few months in a cool place. Winter cabbages are frost hardy and slow to bolt, so don’t feel forced to lift your entire crop if frost is forecast.

Shortly after harvesting, lift cabbage roots to prevent the spread of disease; alternatively simply uproot the whole cabbage when you harvest it rather than just cutting it away with a knife.

Pests of Cabbage

Cabbage root fly

Maggots often cause damage. They hatch from eggs laid on the soil, eat the roots and leave the stumps to rot. Once present, they are impossible to get rid of. To prevent flies from laying their eggs in the first place, use a covering of fleece or fine net or collars around the seedlings. Collars can be purchased or simply fashioned from squares of carpet underlay, cut so they can be slipped around the seedlings. Any eggs laid on the collars will die before hatching.

Cabbage caterpillars

Burrow into the heart and eat holes in the leaves. The caterpillars of the large cabbage white butterfly are yellow, black and hairy; the small cabbage white butterfly pale green and the cabbage moth yellow-green or brown. Pick them off by hand or spray with pyrethrum.

Mealy Cabbage aphids

They are so-called because the grey aphids are covered with white wax. They congregate beneath the leaves, suck the sap, and cause yellow patches and leaf curl. Spray with insecticidal soap, pyrethrum.

Other pests include cutworms, flea beetles, leather jackets, whitefly, slugs and snails, and birds.

Diseases of Cabbage

Clubroot

It is a very serious problem indeed. It is a fungus or mold that attacks roots and, as it kills them, releases spores into the soil. Leaves start to discolor, the plant becomes stunted, and eventually, it dies. What’s worse is that the spores can survive in the soil for up to 20 years and there is no cure.

Preventative measures include systematically rotating crops, burning all diseased plants, improving drainage, liming the soil and planting out only when seedlings are already sufficiently established to be less vulnerable.

Other diseases include downy mildew, powdery mildew, bacterial leaf spot, and white blister.