brassica
tribe
—

The Brassica tribe, also known as Crucifers, are the backbone of our vegetable gardens, mainly grown for use when cooked. However, they also fulfil an invaluable role in salads, and earn their place by being easily grown, nutritious and in many cases colourful. The key is to choose appropriate varieties and growing methods.

Cabbage
Brassica oleracea Capitata Group

Cabbage is among the most widely grown of cool-climate crops, and for aficionados there is a cabbage for every season. In spring there are loose-headed ‘spring greens’ and perky, mainly pointed hearted cabbages; in summer and autumn there are large green and red cabbages; while in winter there are hardy savoys and red-tinged ‘January King’ types, and the option of stored Dutch Winter White cabbage. Any cabbage can be used as a raw salad or coleslaw, especially if finely shredded, but in my view the light green, sweeter spring and summer cabbages, the thin-leaved Dutch Winter Whites, the tasty savoys and the colourful red cabbages are the best for salads, simply because they are the most palatable raw. (For ornamental cabbages and kales see here.)

Typical round-headed early summer cabbage

Typical pointed spring cabbage

Typical green savoy

Cross section of a summer cabbage

Typical red-headed cabbage

–––––
Soil and site

Cabbages require fertile, well-drained, slightly acid soil, though if clubroot is endemic, it should be limed to bring the pH to marginally alkaline. Cabbages have high nitrogen requirements, and are a good crop to follow a nitrogen-fixing green manure. They are among the many brassicas (in the Cruciferae family) that should be rotated, ideally over a three-or-four-year cycle, to avoid the build-up of clubroot and brassica cyst eelworm.

–––––
Cultivation

The most reliable way of raising cabbages is to sow in modules for transplanting, though traditionally they were sown in seedbeds and transplanted. Plant in their permanent positions when quite small, at the three-or-four-leaf stage, planting firmly with the lower leaves just above the soil. Always plant into firm ground, never into freshly manured soil. It is often sufficient just to clear or rake the ground prior to planting, without digging. Otherwise fork the soil several weeks in advance, leaving it to settle before planting. In very light soil or windy, exposed gardens, plant in shallow furrows about 10cm/4in deep, filling in the soil as the plants grow. Secondary roots develop on the buried stem, increasing the plant’s stability. Large plants may need staking during the winter months.

Space cabbages from 30–45cm/12–18in apart, depending on the type and the size of head required. As a general rule, the wider the spacing, the larger the head will be. As cabbages are slow-growing and relatively widely spaced, they lend themselves to intercropping.

Cabbages need plenty of moisture throughout their growth. In the absence of rain, water weekly at the rate of 9–14 litres per sq. m/2–3 gallons per sq. yd. Failing this, aim to give them at least one very heavy watering two or three weeks before harvesting. If growth seems slow mid-season, apply a liquid feed.

Cabbages will often resprout after the main head is cut, producing a very useful crop of smaller secondary heads later in the season (see here). This works best with spring cabbages.

–––––
Sowing programme

For spring and early summer supplies In areas where winter temperatures rarely fall below about -6°C/21°F, sow in late summer, by any method, transplanting seedlings into their permanent positions in early autumn. Space plants 30cm/12in apart for headed cabbages.

For summer and autumn supplies Make the first sowings in gentle heat, at about 13°C/55°F in late winter/early spring, planting out after hardening off as soon as soil conditions allow. (In my previous East Anglian garden, with its low rainfall, I found late winter sowings far better than spring sowings for the main summer red cabbage crop. Seedlings were overwintered in a cold frame and planted out as early as soil conditions allowed in spring.)

Continue sowing in late spring, initially under cover then in the open. Space summer cabbage 35–45cm/14–18in apart, depending on the size of head required. Older varieties of summer cabbages tended to bolt rapidly when mature but improved varieties, such as F1 hybrid ‘Stonehead’, stand in good condition for up to three months. Plant autumn cabbage by mid-summer; space them 50cm/20in apart.

‘Mini’ cabbage These are tiny cabbages with no wasted outer leaves, produced by growing plants very close together. They are exceptionally tender in salads. Only certain varieties are suitable. Sow from early to late spring, in situ or in modules, thinning or planting to 12cm/5in apart. Harvest heads about twenty weeks after sowing.

For winter storage supplies These are mainly Dutch Winter White cabbages, though you can also store late varieties of red cabbage. Sow in mid-spring, planting in early summer 50cm/20in apart. Use heads fresh in early winter, but lift them before heavy frost, pulling them up by the roots or cutting with 5–71/2cm/2–3in of stalk attached to use as a handle. Store them hung in a frost-free shed or cellar, or in cold frames, raised off the ground on wooden slats and covered with straw. Ventilate the frames on warm days. Cabbages can also be stored in heaps on a cellar floor, on a bed of straw with straw between the heads. Inspect stored heads regularly, and gently roll off any rotting outer leaves. They will often keep for three or more months.

For fresh winter supplies These are the hardiest cabbages, surviving outdoors where temperatures normally remain above about -10°C/14°F. The well-flavoured, crêpe-leaved savoys are the backbone of the hardy cabbages; more recently introduced cabbages are crossed with Winter White types. Sow in late spring, planting by mid-summer 50cm/20in apart each way. Some will stand until the following spring, helping to fill the ‘vegetable gap’.

–––––
Varieties

Recent developments in the cabbage world include the introduction of varieties with clubroot resistance, and two groups of exceptionally sweet varieties, the pointed ‘Sweetheart’ types, (indicated with a ‘p’ below which can be grown all summer) and the flat headed, thin-leaved Japanese varieties. I have chosen the varieties listed here primarily for their suitability for salads.

Spring supplies ‘Advantage’ F1, ‘Duncan’ F1, ‘Spring Hero’

Early summer supplies As above plus:

‘Cabbice’ F1 (flat Japanese), ‘Candisa’ F1, ‘Caramba’ F1, ‘Elisa’ F1, ‘Tinto’ F1 (red, p)

Summer supplies ‘Alcosa’ (F1) (summer savoy), ‘Caraflex’ F1 (p), ‘Dutchman’ F1 (p), ‘Elisa’ F1, ‘Regency’ F1 (p), ‘Primero’ F1 (red), ‘Stonehead’ F1

Autumn supplies ‘Charmant’ F1, ‘Kalibos’ F1 (red), ‘Primero’ F1 (red), ‘Ruby Ball’ F1 (red), ‘Stonehead’ F1

Mini cabbage ‘Alcosa’ F1 (savoy), ‘Candisa’ F1, ‘Elisa’ F1, ‘Primero’ F1 (red), ‘Puma’ F1

Winter storage ‘Bison’ F1, ‘Brigadier’ F1, ‘Dutch Winter White Kilaton’ (clubroot resistant), ‘Lodero’ F1 (red, clubroot resistant)

Winter hardy ‘January King Hardy Late Stock 3’, ‘Deadon’ F1

Savoy x Dutch White hybrids: ‘Renton’ F1, ‘Tundra’ F1

Savoys: ‘Cappriccio’ F1, ‘Rigoletto’ F1

–––––
Pests

Unless otherwise stated, for protective measures and control, see here.

Birds Attack seedlings and mature plants, especially in winter.

Slugs and snails Potentially serious at any stage, but most damaging on seedlings and young plants in wet weather.

Cabbage root fly Often a serious pest. Small white maggots attack the roots, causing plants to wilt and die. When planting, take measures to prevent the adult flies from laying eggs near by.

Flea beetle Tiny, blue-black beetles nibble holes in seedling leaves of all brassicas; in situ sowings are the most vulnerable.

Caterpillars Attacks are most damaging in late summer.

Aphids Grey mealy aphids appear on the undersides of leaves in late summer and can be very destructive. Colonies of whitefly, which flutter up from plants in summer, are normally less serious. As aphids overwinter in brassica stumps, and emerge in late spring, old plants should be pulled out and burnt after cropping.

–––––
Diseases

Clubroot This serious soil-borne disease manifests itself as solid swollen galls on roots of the brassica family. Plants eventually wilt and die. Practical measures to reduce clubroot are improving drainage and liming acid soils to a neutral or slightly alkaline level, and rotation. Remember that swedes, turnips and radishes are also brassicas. In badly infected soils grow only fast-growing brassicas such as Texsel greens and oriental cut-and-come-again seedlings. Or give plants a head start on the disease by sowing in modules and potting into 10cm/4in pots before planting out. Watch out for new remedies and resistant varieties.

Damping-off diseases Seedlings are vulnerable when sown in adverse conditions.

Kale
(borecole) Brassica oleracea Acephala Group

I used to think kales were too harsh for anything but the most sparing use in salads. I’ve changed my mind, for several reasons. First, I realized how tender some of the thinner-leaved kales can be, such as ‘Hungry Gap’, ‘Pentland Brig’ and ‘Red Russian’. (The latter has very pretty, blue-green leaves brushed with purple.) Then I discovered two exceptionally beautiful crisp-leaved kales: the old Italian Tuscan kale, also known as cavolo nero, black kale, palm cabbage and dinosaur kale, with its flavoursome, narrow, crêped blue leaves, and the newer ‘Redbor’ variety, probably bred from an old heirloom kale, which is as hardy as the old forms but with striking, deeply curled, bronze-red leaves. And I realized how productive and appealing these, and the traditional curly kales, are when grown as cut-and-come-again seedlings. Indeed, baby-leaved ‘Redbor’ and ‘Red Russian’ are popular ingredients in prepacked salads.

Seedling kales can be sown throughout the growing season, but come into their own in the colder months when salading is most scarce. Two or three cuts of small leaves can generally be made from one sowing. Mix them with other salad leaves, or use them on their own, accentuating their flavours with a strong dressing such as the Ginger and Sesame dressing shown here.

‘Red Russian’ kale

Thin-leaved ‘Hungry Gap’ kale

Thin-leaved ‘Pentland Brig’

Curly kale ‘Redbor’ F1

Typical curly kale

–––––
Cultivation

These rugged kales often succeed where other brassicas fail. They need well-drained, reasonably fertile soil, but are otherwise undemanding. They have some tolerance to clubroot. For mature plants, cultivate as for summer cabbage, sowing in late spring and early summer (see here). Varieties mentioned below are as hardy as savoy cabbages. Mature leaves and the shoots that develop in spring are used as cooked vegetables from autumn to spring, but small leaves could be picked for salads.

For cut-and-come-again seedling crops, start sowing under cover in late winter; continue sowing outdoors from mid-spring to late summer (or later in mild areas). Make the last sowings under cover in early autumn. Kales are relatively slow-growing, but, depending on the variety and time of year, the first cutting of small leaves can be made any time from about six weeks after sowing.

–––––
Varieties

These varieties can be grown as mature plants, but are also recommended for cut-and-come-again seedlings.

Black kale: ‘Black Magic’, ‘Cavolo Nero’

Cavolo nero

Green curly kale (med. sized): ‘Darkibor’ F1, ‘Kapitan’ F1, ‘Reflex’ F1, ‘Starbor’ F1 (compact)

Red curly kale: ‘Redbor’ F1

Thin-leaved kales: ‘Bolshoi’ F1, ‘Hungry Gap’, ‘Pentland Brig’, ‘Red Russian’ and ‘Ragged Jack’ (‘Ragged Jack’ is similar to ‘Red Russian’ in appearance and texture, but may be less hardy), ‘Siber-Frill’ (very curled and indented)

Ornamental cabbages and kales

These loose-headed cabbages and kales are notable for their wonderful colouring: the blue-green leaves are tinged with varying combinations of red, white, cream, purple and yellow. The leaves are also decorative shapes – deeply serrated, frilled or waved – sometimes packed into rosette heads in rings of contrasting colours. Some varieties have been bred with exceptionally long stems for flower arranging. They are all ideal plants for the decorative potager.

They are at their best late in the year, as the colours deepen when night temperatures fall to about 10°C/50°F. There are dwarf, intermediate and tall forms, ranging from 30 to 60cm/12 to 24in tall. Seed catalogues rarely distinguish between cabbages and kales, but those with flat heads and relatively smooth leaves are generally cabbages, while the deeply serrated, coarser-leaved types are kales. The significance is that the kales are hardiest, surviving temperatures of about -10°C/14°F, which would destroy the cabbages. Mainly used in salads as a decorative garnish, small leaves can be eaten whole and larger leaves shredded.

Red ‘Osaka’ ornamental kale

–––––
Soil and site

Soil must be well-drained and moisture-retentive, but these ornamental forms tolerate poorer soil than most brassicas. In rich soil they may become lush and fail to colour well. They like an open situation, but can be protected, or grown under cover, in winter in cold climates. Dwarf types can be grown as winter houseplants in cool conservatories.

For top-quality plants, sow in modules or seed trays, eventually potting into 8–10cm/31/4–4in pots before planting out. Make the main sowings in late spring or early summer; modern varieties take only three months to mature. Space plants 30–40cm/12–16in apart, depending on variety, planting firmly at the five-to-seven-leaf stage, with the lower leaves just above soil level. For a late crop under cover, pot on into 15cm/6in pots and plant in early autumn. For winter container plants, pot dwarf varieties into 15cm/6in pots; or plant two or three closely into a 35cm/14in pot in good potting compost. For pests, see here. Caterpillars tend to be the worst pest (for control, see here).

–––––
Harvesting

Unless using a whole head for decoration, pick individual leaves just before use, as they wilt rapidly. Plants resprout over many months, sometimes lasting two seasons, with small secondary leaves developing on the stems. To perpetuate good varieties, cuttings can be made from young shoots.

–––––
Varieties

Ornamental cabbages and kales are often listed in the flower section of seed catalogues. In each distinct type ‘series’ have been bred, each variety with a different dominant colour, usually red, white, or pink. All are F1 hybrids.

Round leaved Pigeon series, Osaka series, Songbird series

Fringed leaved Chidori series, Kanome series, Nagoya series, Northern Lights series, Buttonhole kale Stargazer

Serrated leaved Coral series, Feather series, Peacock series