The Cabbage Patch
Cabbage is one of our best winter crops, because it likes growing in cool, moist conditions. It is less troubled by pests in winter, and the quality and taste is much better than when grown in summer. Like all brassicas it is rich in vitamin C and is a most economical crop – a little goes a long way when used as coleslaw or in soups and stews. For healthy, good-size cabbage heads, pay attention to watering, fertilising and pest control.
Water before 12:00 to allow plants to dry out by nightfall– they don’t like wet feet. Mulch around plants and keep the soil moist but not too wet, or allow it to dry out completely. In areas with a wet winter it is best to grow cabbage in raised rows for good drainage.
Cabbages are gross feeders. In the early growing stages feed them with a nitrogen-rich fertiliser, but as the heads form they need more potassium. A balanced fertiliser like 3:1:5 or 5:1:5 given once a month or even every two weeks should give the desired results.
If the heads have formed, frost should not be a problem for cabbage. Frost protection may only be necessary in the very cold areas of the Free State and Highveld. Frost-guard cloth can be left on the plants but should be lifted every now and then to check for insects or disease.
Cabbage heads are ready for harvesting when the head is firm, almost hard, to the touch. The head may also be a lighter green. Don’t leave the stump and roots in the ground as they may harbour pests. Rather put them on the compost heap.
Keeping the cabbage cold helps to retain its vitamin C content. Wrap the cabbage in plastic and store in the crisper or in an airtight Tupperware-type plastic container in the refrigerator. Once a cabbage has been cut, the vitamin C content starts to quickly degrade and it should be used within a few days. Cabbage can also
be blanched and frozen. Although it loses its crispiness, it can be used in stir-fries or added to soups and stews
Next sowing of cabbage
The second sowing of cabbage starts in August for the Highveld, Middleveld, the KwaZulu-Natal Midlands and Eastern Cape, and from November to April in the Western Cape and Northern Cape. Start seed indoors in seed trays and only transplant once the plants are sturdy enough.
Pests are less of a problem in winter, but insect activity tends to increase when the seasons change, in this case as it starts to get warmer.
- Aphids suck the sap from the plant and can cause chlorosis, which damages the head. As soon as you see them, spray with an organic insecticide or with a mild solution of soapy water.
- The larvae of diamondback moth (Plutella xylostella) suck sap from tender growth, resulting in a whitish, scarred appearance. A heavy infestation can seriously reduce the growth and yield. The bright green larvae may occur at the base of the cabbage and in the lower leaves. Use a biological caterpillar control like Margaret Roberts Biological Caterpillar Insecticide.
- Thrips also causes damage to the heads and has become a major pest. The larvae are hard to spot so regular preventative spraying with an organic insecticide is recommended.
- Set seedlings into the ground slightly deeper than they were in the tray.
- Enrich the soil with plenty of compost or well-rotted manure before planting.
- Two weeks after transplanting, feed with a nitrogen-rich fertiliser, and continue with regular feeding during the growing season.
- Be on the watch for pests as the weather warms up.