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

outdoors in rows, and the soil is mounded up around the emerging leaves to encourage the tubers to grow. Organic growers approach the challenge of growing potatoes without pesticides by choosing varieties that are less susceptible to disease, such as Valor, Nicola, Cosmos, Desiree, Charlotte, Raja and Saxon, and, increasingly, by growing the new, blight-resistant organic varieties that are being developed. Instead of using chemical fertilizers, they grow potatoes in long rotations, interspersing them with other crops. Organic potatoes are often planted after a crop such as red clover, that naturally fertilizes the soil, and the soil is then dressed with manure. Jersey Royals, though not organic, are treated with a natural seaweed fertilizer called ‘vraic’.

      Most older potato varieties are very prone to blight (see Are potatoes a green choice?), so although they can be grown organically on a back-garden scale, they are susceptible to crop failure when cultivated on a more commercial scale.

      Are potatoes a green choice?

      An underlying problem with potatoes is their narrow genetic base. There are some 150 different species of potatoes in the Andes where the potato family originates, but all the potatoes grown outside that region come from one sub-species. This lack of biodiversity, or genetic similarity, leaves the world’s crop more susceptible to disease, in particular, blight, the same devastating fungus that caused the Irish potato famine of the 1840s and which destroys 20 per cent of the world’s annual potato harvest.

      One solution advanced for blight is genetic modification, but this is extremely controversial. The leading International Potato Centre in Lima, Peru, has imposed a moratorium on planting GM potatoes in South America because of fears that genes introduced into GM potatoes might escape into wild potatoes. Meanwhile, plant breeders in Hungary and Scotland have already come up with a non-GM solution, successfully breeding blight-resistant new varieties, such as the organic Sarpo Mira and Axona, using conventional breeding techniques. These new organic varieties have shown unprecedented blight resistance and also virus resistance, while other supposedly blight-resistant varieties, such as the ubiquitous Sante and Cara, have been wiped out within weeks. Biotech evangelists love to make out that only their industry has the solutions to intractable farming problems like blight, but here’s a glowing example of how it is possible to breed a crop with a desirable trait without using highly unpredictable GM techniques, such as the introduction of antibiotic resistance marker genes, that open the door to major environmental and health risks.

      POTATOES WITH A SENSE OF PLACE

      For as long as anyone can remember, the potato has been a stalwart ingredient in the British and Irish diet. Back in the Second World War, it was considered such an essential, healthy food that potato growing became a key plank in the British strategy for survival. It figured prominently in the Ministry of Food’s ‘Dig For Victory’ campaign, which enlisted a cartoon superhero, Potato Pete, to encourage the nation to grow and eat more potatoes, successfully doubling the acreage planted. Nowadays, only the Portuguese and the Irish eat more than we do.

      Potatoes grow quite well in our climate and Britain has always been a leading centre of expertise in potato cultivation and breeding. Some rare, traditional potato varieties are still in small-scale commercial production, popular with allotment holders and gardeners and very much in vogue with chefs. Taste them blind, and the taste contrast with the standard spuds we eat is striking. They look discernibly different too. Some have deep-set eyes, others thick, netted skin – like the scruffy East End cousins of cosmetic modern varieties. Their skin tones employ a palette of colour from mercury black through rosy pink to midnight blue. Their flesh can be alabaster white, butter yellow, imperial purple, indigo or claret. Their shapes go from elongated and knobbly via oval to round and smooth. Their names have all the interest of a Grand National line-up: Highland Burgundy, Kepplestone Kidney, British Queen, Edzell Blue, Red Duke of York, Purple-Eyed Seeding, Epicure, Shetland Black, La Ratte, Peachbloom, Pink Fir Apple, Red King Edward, Witchill and Mr Little’s Yetholm Gypsy, to mention a few. These are potatoes steeped in history and traditions, potatoes with a sense of place.

      Where and when should I buy potatoes?

      The potato year begins with the arrival of ‘new’ or ‘early’ potatoes. They are lifted young when they still have thin skins that can be rubbed off with the fingers and their consistency is slightly waxy. In February, imports from Egypt, Israel and Cyprus start arriving in shops, followed by Jersey Royals in March then Cornish and Ayrshire varieties in May and June. If you want to reduce unnecessary food miles, then stick with UK new potatoes: they are worth waiting for. Next come the ‘second earlies’ grown in colder, more frost-prone areas of the UK, followed by early ‘maincrop’ potatoes in August, then the true maincrop potatoes that come on stream in September and October. These maincrop potatoes have a higher dry matter content than earlies and thicker skins. They can be sold directly from the field or kept in cold storage throughout the winter to preserve them until the next year’s home-grown new potatoes become available.

      Supermarkets are now stocking a few more interesting ‘heritage’ varieties, but for a better range check out specialist potato suppliers and look out for more unusual, characterful varieties at farmers’ markets.

      Will potatoes break the bank?

      In early spring, before the new season’s Irish- or UK-grown potatoes are available, imported new potatoes go on sale. These can make the maincrop potatoes from the season before look rather old, but they will still be fine for most purposes – they just need to be peeled – and will cost a fraction of the price commanded by the new, more attractive-looking imports.

      You pay an awful lot for the privilege of having your potatoes pre-prepared. Products such as ready-made gratin, baked potatoes and fried wedges come with a huge mark-up. Save a small fortune by making your own at home. And, of course, they will taste better.

      Don’t throw away older potatoes when they start sprouting. This happens naturally when maincrop potatoes are stored over winter. Just knock off the sprout and use the rest of the potato. Don’t use potatoes with large green areas, as these have been exposed to light and could be slightly poisonous. It’s fine, however, to eat potatoes with only a little patch of green on them. Simply cut it off.

      Spinach and Swiss chard

      For a concentrated blast of greenness in your diet, spinach is hard to beat, a supremely versatile leaf that earns its keep both cooked and raw. There are two sorts of spinach. The most common type in shops is true spinach, sometimes called summer spinach, which is fine, silky, tender and smooth when cooked. It has an affinity with cream, eggs and both mild and pungent cheese. A coarser type of spinach, known as perpetual or winter spinach, is more often grown by gardeners, or supplied by small-scale growers in vegetable boxes or at markets. It is slightly less green, with a less pronounced spinach flavour and is more fibrous. If you want elegant spinach, then perpetual spinach isn’t it. For cooking purposes, it is better treated like spring greens, lightly blanched and then dressed with oil or butter, or stir-fried.

      Swiss chard is excellent when cooked and hugely under-appreciated. You can think of it as two vegetables packed into one. Its pearly central stalks offer a unique taste that bears some comparison with artichoke, palm heart and salsify. The green leaves, which initially seem quite coarse, will soften down beautifully when sautéed gently. Rainbow chard has red and yellow central stalks, but it tastes the same as the white-stalked sort.

      Things to do with spinach and Swiss chard

      • Pearly central stalks of Swiss chard make a fantastic creamy, cheesy bake.

      • The classic eggs Florentine tops a half muffin with buttery cooked spinach, a poached egg and hollandaise sauce.

      • Chopped or blitzed cooked spinach adds thickness, texture and colour to curries and Middle Eastern stews.

      • Make a salad by throwing garlic-rubbed fried bread croutons on baby spinach leaves dressed with olive oil, lemon juice, sea salt, and lots of black pepper and Parmesan.

      • Spinach goes brilliantly with ricotta cheese. Use as a filling for cannelloni topped with béchamel sauce, or to make Italian green gnocchi, or as a filling for a vegetable tart.

      • Chopped Swiss chard, both