Cabbage is packed with minerals and vitamins and is worth the effort it takes to cultivate, says Jane Powers
I stole a cabbage once. I wrenched it from the soil in a neighbour's garden, to impress a boy who had dared me to do it. Now, decades later, I can't even remember the name of the boy, but I do remember the cabbage, extremely well. It was huge and heavy, a vegetable cannonball wrapped in dark-green leaves: the largest in the plot. Its memory sends a chill of remorse through my core. I know now what I didn't then: that its grower would have been minding it for the best part of a year, which would have made its senseless theft all the more infuriating.
Cabbages are slow growers. They are biennials, building up a nutrition-rich mass of leaves in their first year, and using that store of energy to flower and set seed in the second. But few live out their full potential, because we harvest them at the point when they have stockpiled the most goodness. Nonetheless, they may be in the ground for six, nine or more months. Vegetable expert Joy Larkcom says that red cabbages take the longest. She recommends sowing seed in autumn in a greenhouse, frame or polytunnel, and planting out the infants in spring.
The cabbage may seem like a melancholy, northern vegetable - indeed it grows best in cooler weather, disliking hot sun and dry conditions. But, in fact, its wild forebear, Brassica oleracea, lives on sea cliffs of the Mediterranean and southwestern Europe (including southern England). It has been cultivated as a food crop for thousands of years: the ancient Greeks believed that it sprang from the sweat of Zeus.
The cabbage of today is a completely different-looking item to that eaten by the Greeks and Romans: theirs was looser and leafier, more like kale. But, as it happens, both kale and cabbage are the same species, B. oleracea. And so also are broccoli, Brussels sprouts, calabrese, cauliflower and kohl rabi. All originated from a single wild plant species, and were developed by selection, and latterly (in the last century or so) by breeding. Turnip, swede and oriental brassicas (such as mizuna and pak choi) are different species, however.
Brassicas have been in the news over the last few years because of research showing that the mustard oils they contain help to prevent cancer. They are also packed full of minerals and vitamins - a very good reason for growing and eating your own greens.
The cabbage family grows best in a cool, moisture-retentive and fertile soil. According to Joy Larkcom, its members don't like freshly-dug, or freshly manured ground - so any digging should be done weeks in advance. If your soil is light and inclined to dry out, water it thoroughly and cover with a mulch (straw, leafmould, newspaper, for example) after planting. Most brassicas are top-heavy vegetables, and need a good grip on the ground if they're not to keel over. Some, such as sprouting broccoli and Brussels sprouts, should be earthed up around the stems, or even staked, for support. In light soil, brassicas can be planted in shallow trenches, which should be filled in as the plants grow. This encourages extra roots to form along the stems, helping to stabilise the plants and to make them more resistant to cabbage root fly, the larvae of which attack plants below ground.
Brassicas are martyrs to pests and diseases, but vigilance and planting out at non-peak pest times are good methods of management. Cabbage root fly can be prevented from laying eggs by protecting the bases of plants with disks of carpet underlay, or other heavy material. Aphids can be whooshed off with a hose, or removed by hand. Caterpillars may also be hand-picked, as can slugs and snails. Wood pigeons can devastate a crop, and only a net will definitely keep them away.
If you grow a great crowd of brassicas together, you're sending out a dinner invitation to every cabbage-family-nibbler for miles. So, companion planting (interspersing them with other plants) is an effective way of befuddling pests.
As for diseases, the most feared is the medieval-sounding clubroot, caused by the slime mould Plasmodiophora brassicae. It causes the roots to swell grotesquely, and the plants to become stunted, with drooping leaves. It is more likely to flourish in acid, water-logged soil, so liming and adding compost may help prevent it. Clubroot can remain active in the soil for up to 20 years, and may survive in related plants, such as wallflower and stock, and in the weeds charlock and shepherd's purse.
You can bring it in to your garden on your boots or garden tools, or - more likely - on plants. So don't accept or buy young brassica "transplants" unless you know they are disease-free. A new cabbage, 'Kilaxy' (from Suttons Seeds), is supposed to be resistant to clubroot, while the Royal Horticultural Society suggests that calabrese 'Trixie', Chinese cabbage 'Harmony', and kale 'Tall Green Curled' are partially resistant.
An essential tool for avoiding brassica problems is rotating crops, preferably over four years. If you grow them after legumes (peas and beans), you'll take advantage of that group's ability to fix nitrogen in the soil.
You can also avoid trouble if - and here's advice from Joy Larkcom again - you grow fast-maturing brassicas. Texsel greens (available from Brown Envelope Seeds) are a spinachy-cabbagey-flavoured Ethiopian mustard (Brassica carinata) with a hint of garlic, and they can be in and out of the ground before problems strike. So also can most Oriental greens, which can be eaten as salad leaves, or used in stir fries. If you had sown them in autumn (and given them a little winter protection), you'd be tucking into them now. "The nice thing about the orientals," says Joy, "is the range of flavour, from the mild pak choi and Chinese leaves to the very spicy 'Green in the Snow' mustard."