The family plot

Springtime for fruit and vegetables. Anna Pavord, The Independent's gardening writer, says their decorative uses are undervalued

A dilettante gardener may grow a passable show of flowers. Vegetables indicate a deeper level of commitment. We may no longer have to feed ourselves from our plots, but without growing fruit and vegetables we lose out on some of the great pleasures of gardening. Think of the sense of pride when you sit down to a supper made entirely with the produce from your own plot. (After the pride, of course, comes the fall, when somebody finds a caterpillar, mummified, in the artistically arranged spears of calabrese on their plate.)

It is only quite recently that vegetables and fruit have been separated from flowers in the garden, and that the kitchen garden has acquired its drear overtones of overblown cabbage. It could all be different, as George Eliot reminds us in her novel Scenes from Clerical Life. She talks of a kitchen garden where "you gathered a moss- rose one moment and a bunch of carrots the next; you were in a delicious fluctuation between the scent of jasmine and the juice of gooseberries." To recapture that sense of delicious fluctuation, bring flowers back to bloom among your fruit and vegetables this summer.

Try planting purple-headed alliums among your leeks, set purple aquilegias around your red cabbage, grow marigolds with curly-leaved lettuce, lay down rows of blue cornflowers between your fennel and your carrots. Certain annual flowers, such as marigolds and nasturtiums, have a special affinity with vegetables, for they too can be eaten, the petals of marigolds sprinkled over a mixed salad, the leaves and seeds of nasturtiums adding extra spice to a sandwich.

Flavour is the prime criterion of any fruit or vegetable. But you can look for other attributes as well. Among leeks, for instance, there is an extremely handsome cultivar called Bleu de Solaise (also known as St Victor) which is hardy, and wonderful to eat. The bonus is its foliage, leaves of a rich, purplish-blue that you can use to great effect among the pale, frizzed foliage of endive. Verbena bonariensis, with purple heads of flowers on tall, wiry stems, is another good companion for leeks. Mix the two in a patch and edge them round with low-growing, monkey-faced violas.

There are early, mid-season and late varieties of leek, the early ones tending to be tall and thin, the late ones squat and fat. Main sowings should be made in drills outside, during March. Sow seed as thinly as possible, half an inch deep. At the end of June, or in early July, lift the baby leek plants and drop them one by one into holes that you have made with a dibber. The holes should be about six inches deep and six inches apart in rows about a foot distant. Fill the holes with water, to wash soil over the roots of the young plants. Sometimes you can buy bundles of young leek plants ready to put in, which gives you absolutely no excuse not to grow them.

Runner beans are equally easy, and can also be used to great decorative effect. Grow the old red-and-white variety, Painted Lady, up a tripod in the flower border, mixed with white clematis. Bend hazel poles over a path to make a lattice work tunnel to support a mixture of runner beans and spectacular, late-flowering purple cobaea or flame-coloured Eccremocarpus scaber. Make a wigwam of beans the centrepiece of a pumpkin patch, and surround it with a border of bright nasturtiums.

Start thinking about the bean's planting-site six months before you sow, and dig masses of well rotted manure or compost into the soil. Runner beans are deep rooted, and their roots like to feel the journey has been worthwhile. Do not be in too much of a hurry to sow, as the soil temperature must be at least 10C (50F) if the seeds are to germinate. This rarely happens before mid-May.

Set seeds six inches apart round a wigwam, or along a row of hazel poles, and water liberally during the growing season. Runner beans are not difficult to raise, but in some seasons they seem reluctant to bear fruit. Spraying the flowers with water does not help as much as keeping the roots moist. Less easy to cope with are pollen beetles, which move on to runner beans (and sweet peas) when oilseed rape has finished flowering. Sitting in the keel of the flower, they discourage visiting bumblebees and the flowers are left unpollinated.

Of all decorative vegetables, lettuce is the most versatile, because it presents itself in so many different guises and adapts itself to so many uses in the garden. The frilly, loose-leafed kinds can be used as foliage plants between groups of annual flowers, or to add bulk to billowing, daisy-covered argyranthemums in a window box. You can plant Red Salad Bowl to line paths or edge a raised bed, or use a small butterhead such as Tom Thumb, which is all heart, to fill beds in a modest parterre. Crisp, crunchy Windermere will frame tomatoes in a Gro-Bag.

In theory, if you sow lettuce seed every fortnight from spring until midsummer you should have a non-stop supply of salads until autumn. In practice, lettuce either bolts or sulks, and you end up with the usual chaos of feast or famine. Sow seed little and often in drills outside, in rows six inches apart for small cultivars such as Little Gem, a foot apart for large types such as the loose-leafed lettuce Lollo Rossa. Thin small types to six inches apart, large ones to a foot apart. Lettuces need plenty of water while growing, but not too much feeding. Excess nitrogen makes them taste bitter. Water in the morning rather than the evening, so that leaves dry off quickly and are less prone to attacks of downy mildew.

Trained fruit trees give to the kitchen garden what clipped yew hedges and topiary give to a flower garden: good structure. Apples and pears can both be trained to make living screens between one part of the garden and another, or to provide a fruitful backdrop for a border of old-fashioned flowers.

The shape of tree you buy - bush, standard, cordon, fan or espalier - depends on where you want to put it. Bushes start fruiting when they are young, and the fruit are easy to pick, but they will never have the satisfying shape of a full-blown standard. Cordons trained against wires make an excellent screen. Although they will not crop as abundantly as a big tree, this is an excellent way of growing fruit in a restricted space.

Train trees as fans or espaliers to make outdoor rooms. Half-standards (with a stem of at least four feet) and standards (with a stem of six feet) look good in lawns. Picking is slightly difficult, but the trees are pleasing to look at and, when established, can be used as props for roses or clematis.

Pears are amenable creatures to train, easier than apples which generally have a stiffer habit of growth. They will pay rent twice a year, with spring blossom and an autumn harvest. Compared with a Japanese flowering cherry, this is rather generous. And pears grow old gracefully, welcoming lichens to their capacious branches. In winter, they assume the gnarled shapes of avant-garde sculptures.

The wild pear, Pyrus communis, is a deep-rooted tree, able to make the best of poor soils. Most pears that you buy, apart from half-standards, have been grafted on to a quince rootstock. This restricts the tree's size and brings it into fruit more quickly, but the tree is shallow-rooting and needs good soil.

Plant in autumn, when the trees are dormant. Fruiting may depend on the effort you put into arranging a decent sex life for your pear. Relatively few are self-fertile; flowers must be set with pollen from a neighbouring tree. Cultivars can be sorted into three pollinating groups, depending on the time of flowering. For effective cross-pollination, choose pears, such as Beurre Hardy and Doyenne du Comice, that come from the same group.

Vines, like pears, have their hearts in a warmer country than ours, but in a decorative kitchen garden you are as likely to plant a vine for its foliage as for its fruit. The leaves have great style and the wayward, exuberant way that a vine grows gives a sense of generosity in a garden.

In cooler climates, serious grape fanciers may grow their vines in a greenhouse, training out the rods and assiduously thinning bunches of grapes as they swell. Grown outside, the fruit may not be flawless, but the foliage can be given its head.

Train a vine over a seat or an arbour to give shade in summer. Plant one on a pergola with a clematis to lend its flowers to the vine's superb foliage. Vitis vinifera, "Purpurea", provides a contrast for a scrambler such as Clematis flammula, or you could combine its purple leaves with pale blue clematis and a deep red climbing rose. Unfortunately, the most spectacular vines are not those with the best grapes: you will have to decide which is more important, appearance or taste.

Concord, the hardiest of the fruiting vines, may survive outside in areas where more tender Vitis vinifera types, such as Muller-Thurgau and Siegerrebe, will shiver and sulk. In this country, outdoor grapes rarely succeed north of a line drawn from Gloucester to the Wash. Correct pruning and training are essential, whether you are growing grapes inside or out. In a greenhouse or conservatory, vines trained on rods against the ribs of the roof provide useful natural shading.

Soft fruit is rarely trained into decorative shapes, but redcurrants make attractive double cordons, shaped like wine glasses, and gooseberries can be grown on single stems to make round-headed standards. Use them as a centrepiece, to mark the corners of a herb garden, or to give height to a flower border. Grown on three-foot stems, gooseberry bushes have a sculptural quality; they are enchanting if you leave the berries to hang and ripen until they are as richly coloured as amber.

Plant the bushes in sun or partial shade, between late autumn and early spring, on well drained but moisture retentive soil. Mulching with manure or compost in early spring will conserve moisture.

Gooseberry bushes do not need regular pruning, but it is easier to pick the fruit if you remove some growth from the centre of the bush each winter. American gooseberry mildew is the only debilitating disease. Keep it at bay by planting a disease-resistant variety, such as Invicta. The fruit freezes beautifully. In winter, re-create the authentic taste of early summer by baking a crisscross-latticed gooseberry pie.

Adapted from 'The New Kitchen Garden' by Anna Pavord, published by Dorling Kindersley, price pounds 16.99