Seeds (Brassica oleracea var. capitata f. rubra)

Red cabbage (Brassica oleracea var. capitata f. rubra) is the deep purple-red member of the cabbage family, prized for its dense, tightly-wrapped heads and crisp leaves shot through with vivid magenta. It carries the same fresh, faintly peppery cabbage bite but with a slightly sweeter finish, and its colour holds beautifully — making it a favourite for crunchy slaws and salads, jewel-toned pickles, and slow-braised dishes where the rich red turns to a glossy violet. Beyond the plate, its bold rosette of glaucous purple leaves makes it just as handsome in an ornamental winter bed.

Planting

Cabbage is a cool-season crop. In cooler climates, start the seeds indoors roughly 4 to 6 weeks before transplanting in early spring, or sow directly for a fall crop in early July; the RHS calendar runs summer cabbages February to April, autumn/winter types April to June, and spring cabbages in July. When sowing in modules or indoors, set the seed about 1 cm deep, increasing to roughly 2 cm deep for outdoor drills. Germination is best at a soil temperature of about 10-29 C, with seedlings emerging in around 15 days at 15 C, 9 days at 20 C, and 6 days at 25 C; indoors, a normal room temperature of about 16-21 C with bright light gives the strongest early growth. Move seedlings outdoors after about five weeks, once they stand 10-15 cm tall with five or six true leaves. Choose a sunny site — cabbage performs best in full sun though it will take light shade for part of the day. Space compact varieties about 30 cm apart and larger ones up to 45 cm apart, in rows roughly 60-75 cm apart (Harvest to Table suggests 45-61 cm between plants in rows 61-91 cm apart). In Egypt, grow it as a winter vegetable rather than in summer: raise transplants from late August through October and plant out September to November so heads mature in the cool November-February window when temperatures sit in the favourable 10-20 C range. Across the Nile Delta and Lower Egypt — Cairo, Alexandria and Beheira — the mild winter is ideal, with a main September-October sowing for a December-February harvest and a workable later sowing into November since frost is rare. In Upper Egypt (Asyut, Sohag, Luxor, Aswan), push the schedule a little later, sowing October-November so heading falls in the coldest part of the season and avoids early heat. Avoid a spring crop that would head after February-March, as rising heat causes loose heads, splitting and bolting.

Fertilizing

Feed with a nitrogen-rich fertiliser once the plants have settled into their final position but before they begin to form heads. Extension guidance is to side-dress with nitrogen about 2 to 3 weeks after transplanting, once plants are well established (for example around 0.34 kg of urea, 46-0-0, per 30 m of row). Go easy on nitrogen late in the season, as a heavy late feed can cause the heads to split.

Care

Keep the plants steadily watered, providing about 2.5-4 cm of water per week (one inch works out to roughly 60.5 litres over the bed); for established plants, the RHS advises a thorough soaking about every 10 days during dry spells. Spring cabbages raised in a seedbed are first spaced 10 cm apart, then thinned in late February or March to about 30 cm. Watch for the usual cabbage pests — cabbage caterpillars (imported cabbageworm, cabbage looper, diamondback moth), cabbage root fly or cabbage maggot, flea beetles, mealy cabbage aphid, whitefly, and slugs and snails — and stay alert for the main diseases: clubroot, black rot, and Alternaria leaf spot. Harvest once the head is firm and has reached a usable size, cutting with a sharp knife when it feels solid and its base measures about 10-25 cm across. Cabbage matures in roughly 60-100 days from transplanting (about 70-120 days from seed), depending on the variety.