What to Eat: Food that’s good for your health, pocket and plate. Joanna Blythman

and bone health; soluble fibre, which slows down the rate at which sugar is released into the bloodstream; and folate, which helps prevent birth defects. In addition to all this, brassicas contain a collection of useful minerals and phytochemicals, such as sulforaphane and indoles, which are thought to have a strong anti-cancer action, and have an anti-inflammatory effect, which is believed to help reduce the risk of heart disease and stroke.

      If you want to lessen your exposure to pesticide residues, choose organic brassicas. If this isn’t an option, discard more of the outer leaves than you usually would as they are more likely to trap residues from spraying.

      How are brassicas grown?

      Brassicas are grown all over the UK and particularly thrive in coastal areas. Most production is centred on Lincolnshire, Cornwall, Lancashire, Kent and the east of Scotland. The robust, hardy brassicas – cabbage, cauliflower, romanesco, kale, broccoli and Brussels sprouts – are usually grown in open fields, although they can be started off in an open, unheated polytunnel then transplanted for an early crop. More tender, leafy brassicas, such as pak choy, are commonly grown in greenhouses or polytunnels. Some brassica growers specializing in indoor production are now using hydroponic methods, where the vegetables are grown, not in earth, but in a soil substitute and nourished with water and nutrients.

      Are brassicas a green choice?

      Since brassicas grow well in the UK, there is never any need to eat the imported sort. These come from further afield, using up lots of oil in transport, so they leave a heavier carbon ‘foodprint’ than home-grown. Most imported brassicas come from dryer countries such as Spain where water usage in crop production has put further pressure on already depleted water resources.

      Brassicas are very susceptible to insects, pests and diseases, so unless they are organically grown, they are likely to have been given repeated pesticide treatments. These can pollute soil and water and have a negative impact on wildlife. Non-organic British brassica growers are trying to reduce their dependency on pesticides, not least because several products they relied on are being phased out or restricted by the European Union. They are using various techniques to minimize spraying as well as regular crop rotations (not growing the same crop in the same place for too long) to prevent any pest build-up in the soil. That said, many conventional brassica growers still use several controversial pesticides that most consumers would probably prefer were not used to grow their food.

      Polytunnel and glasshouse production of brassicas can raise a number of environmental issues too (see TOMATOES/Are tomatoes a green choice?).

      Where and when should I buy brassicas?

      British-grown brassicas are either in season or available from store as below. If you see these vegetables at other times, they are likely to be either imported or grown in heated glasshouses.

      Cabbage: all year

      Cauliflower: all year, best in summer

      Spring greens: March to June

      Brussels sprouts: October to March

      Broccoli (calabrese), romanesco: June to October

      Purple sprouting broccoli: January to April

      Chinese greens: March to December

      Kale: September to March

      Kohlrabi: July to February

      Radishes: March to August

      THE SMELL OF SCHOOL DINNERS

      Although cabbage and cauliflower have long featured in the British diet, unlike other cultures, we rarely celebrate them. Indeed, many people have an antipathy to them. Koreans go mad for pickled fermented cabbage, kimchee. Eastern and central Europeans celebrate sauerkraut. Say cabbage or cauliflower to British people, and you are more likely to hear remarks about the sulphurous school dinner smell of over-boiled vegetables.

      In recent years broccoli, which was rarely eaten in the UK until the 1980s, has become the country’s favourite brassica and a whole range of leafy vegetables once seen as oriental, and only available in Chinese supermarkets, is now being cultivated in the UK. As sales of these newer vegetables have boomed, production of the more traditional cabbages and cauliflower has declined. The area in the UK now planted with these crops has shrunk substantially, partly as a reflection of reduced demand, and also as a consequence of supermarkets paying growers unsustainably low prices for crops, which they then sell with a very healthy profit margin. This is a great pity, because, thoughtfully cooked, these are vegetables any nation should be proud of. Recently both cauliflower and cabbage (the latter often reinvented as ‘seasonal greens’) have earned the patronage of top chefs. Combined with the growing interest in local food, the fortunes of these two familiar vegetables may yet revive.

      Will brassicas break the bank?

      Since vegetables such as purple sprouting broccoli, spring greens and cavolo nero have become fashionable and calabrese has been hailed as a ‘superfood’, their price in supermarkets has increased noticeably. But in markets, farm shops and independent greengrocers, you can usually buy them for less, with a price tag that more accurately reflects the current wholesale price.

      Probably because fewer people can think of something to do with them, radishes, kale and kohlrabi are notably cheap, so they are particularly good buys.

      Hard white and red cabbages keep really well in the fridge, so ignore use-by dates that suggest otherwise. Although other brassicas are best eaten nice and fresh, there are ways to rescue those that haven’t yet started to yellow, but are nevertheless past their prime. You can strip off and discard the floppier outer leaves of loose-headed cabbages and sprouts and use just the heart. Few people will notice that cauliflower isn’t as fresh as it might be when it’s cooked in a curry. Cut out any hard ribs and stems on brassicas that are green and leafy, such as spring greens and kale, wilt them in salted, boiling water, then drain them and dress with olive (or nut) oil and lemon juice or a splash of vinegar, in the style of that Greek staple, horta vrasta.

      Carrots and other root vegetables

      (parsnip, swede, white turnip, celeriac, sweet potato, Jerusalem artichokes)

      Root vegetables have a reliable, comforting sweetness. They work well together, each one enhancing the other’s flavour. People who find them boring have often had bad experiences with eating ones that were watery and fibrous because they were boiled or steamed. With the exception of soup, where their flavour and perfume suffuse the liquid, water is their enemy. You get the best from root vegetables when you fry, sauté, roast, bake or stew them, or, in the case of carrots, beetroot, Jerusalem artichokes and celeriac, eat them raw.

      When it comes to carrots, mature, deep orange-coloured ones will be the sweetest and most flavoursome. Unwashed carrots are likely to taste better than washed ones. The soil may be a pain to wash off, but it really helps to protect the roots and keep them moist and firm in storage. It can be surprisingly hard to get decent-tasting carrots in supermarkets. Sweetness is often lacking and they can have a flat, almost soapy taste. This is partly a reflection of their growing method but also a consequence of our large chains’ body-fascist vegetable specifications that are driven by cosmetic appearance. They stipulate that carrots must always be of a similar length and girth, washed and looking appetizingly orange, fresh and wet. To achieve this look, they have to be washed and rotated in a vegetable-processing machine, a bit like a domestic washing machine. The considerable agitation involved in this treatment weakens the carrots and when they are then wrapped in plastic bags they deteriorate further. This is why many supermarket-bought carrots go soft and rot in parts. If you buy carrots washed, take them out of their plastic bag to allow the air to circulate around them and keep them in the fridge.

      Tender, young baby carrots have their appeal, but they are never going to be heavy hitters in the flavour stakes unless you get them from the garden, when they can be a delicate treat. Slender, new carrots, usually sold in bunches with their green leaves still attached, look rustic, but they are a bit of a gimmick. Their taste is mute compared to properly mature carrots.

      Pre-prepared carrot sticks sold in puffy ‘pillow packs’ may look fresh because they have been stored in