I used to be one of the irritating things about using American cookbooks: an instant ingredient problem. Blueberry pie, blueberry muffins, blueberry cheesecake . . . they all sounded so good, but where could you lay hands on half a pint of fresh blueberries, even in the middle of a British summer?

But these firm little berries with their powdery bloom, once a thin blue line destined primarily for the up-market restaurant trade, are making their presence felt this summer in supermarkets, and even at the corner fruiterer.

It would be an exaggeration to say that blueberries are flooding the market, but they have certainly never been so available. And a substantial proportion of them are English. How come?

The man we have to thank for the advent of this delicious and versatile fruit in Britain is David Trehane, a Dorset-based market gardener and nurseryman who was the first, and until recently the only, British fruit grower to see the English potential in what was widely regarded as a North American fruit.

In 1949 he was one of six British growers who took up a trial offer from the University of British Columbia in Canada, of 80 free blueberry plants to any grower who cared to try them out. Only Mr Trehane persisted, setting up the first commercial plantation of English blueberries in 1957.

Now his son, Jeremy, oversees an annual production of 25 to 30 tons in a six-week growing season from mid-July until the end of August. Mr Trehane's 'Dorset blues' are widely regarded as top of the range, beating the summer opposition of Dutch and French blueberry imports hands down. Jeremy Trehane is in an enviable position. 'We are being wooed by supermarkets begging us to supply them,' he says.

For the Trehanes it is a puzzle why more growers did not see the potential of the blueberry in Britain. But its image as an alien fruit persists. When I spoke to Jeremy Trehane, fresh from the New Forest Show and dashing from one delivery to another, he had just spent three days talking blueberries to other growers and consumers. 'People ask what they are. Often they think they are sloes. Neighbours of ours still cannot

believe there are blueberries on the doorstep - they think blueberries can only be grown in North America.'

The type Mr Trehane grows from those original Canadian plants is known as the highbush blueberry, native to the Great Lakes of North America. It is related to what the English call bilberries, the Scots call blaeberries and the French call myrtilles sauvages.

But unlike these other members of the family, Dorset blues and the North American blueberry are cultivated.

They are larger, sweeter and firmer than their wild relations. This gives them admirable keeping qualities. (Cultivated blueberries will keep in the fridge for considerably longer than raspberries or strawberries: more then seven days, if you get good ones.)

Lovers of the wild blueberry would doubtless defend its merits against this cultivated newcomer. Wild blueberries, such as the myrtilles sauvages found in profusion in summer in shady spots in the wilder and higher regions of the Vosges mountains and Ardeche in France, are smaller, contain more pips and will not last as well.

A encounter with wild blueberries will leave you with blue fingers and lips; the cultivated variety will not. But the flavour of wild blueberries is much more perfumed and intense. In comparison, cultivated blueberries can taste almost insipid.

But for the ordinary consumer, cut off from nature and more likely to take a ramble around the local supermarket than a mountain range, the arrival of affordable blueberries to scatter on breakfast muesli, enliven a fruit salad, or simply consume unadorned, is a boon.

Blueberries are good for you, too: high in vitamins A and C, with beneficial astringent, antiseptic and mildly laxative qualities. They are thought to have a positive

effect on the intestinal tract and are often recommended as preventive medicine against urinary- tract diseases.

Other factors give blueberries a sound bill of health. Because the highbush blueberry is a relative newcomer to Britain, it does not attract many pests and diseases that require chemical treatment. Unlike raspberries, for example, where endemic problems such as raspberry root-rot disease result in ever stronger inputs of pesticides, and up to 10 chemical treatments of canes and berries in one growing season, blueberries are relatively trouble-free. Well-tended bushes will go on for decades.

Jeremy Trehane takes great pride in the fact that his father's original plantation, dating back 35 years, is now dedicated entirely to organic production, destined for Sainsbury's. 'The blueberry lends itself to organic production. Even our non-organic blueberries need only treatment against caterpillars and one weedkiller treatment,' he says.

But apart from having what he calls 'a natural aversion to splashing chemicals about', Mr Trehane sees his organic production as an important step in keeping ahead of the game. In effect, he has made a commercial decision. 'This year, the blueberry market has become a buyers' market, with huge imports of Dutch and French blueberries flooding Britain. The varieties are not as good as ours - they can look a bit pudgy and are often over-handled because they have been mechanically harvested, then had a longer journey.'

Like his father before him, Mr Trehane is a man of vision, 'I saw the availability of blueberries increasing and I knew that, if we were going to keep our lead, our good name, and our nose in front, we had to concentrate on quality, not volume. That means hand- picked fruit, the best varieties, and fast distribution.'

With Trehane's Dorset blues looking like the sort of business development success that would please everyone from the bank manager to the Ministry of Agriculture, you may wonder why growers are not rushing to plant this most promising and buoyant of summer fruits. The cultivated blueberry thrives in Britain on very acid soil. Dorset blues are grown on eight acres near Wimborne in Dorset, on the edge of unploughed heath which has never been under pasture. (Mr Trehane has also planted another seven acres in Ireland.)

This characteristically poverty- stricken land, not useful for any other agricultural purpose, is the sort of environment in which British blueberries flourish. But nowadays, such heathland is mostly under environmental protection at a European Community level, and very little is available.

A British blueberry glut simply cannot happen - there is not enough of the right kind of land about. Perhaps that is all to the best for the British blueberry's future. The Trehanes' Dorset blues are certainly setting the standard, but production will remain relatively small, seasonal and special. Commodities of that kind are very precious.

Trehane's Dorset blues are sold by Sainsbury and Marks & Spencer, and direct from Trehane's High Mead Farm Shop, Ham Lane, Longham, Ferndown, Dorset BH22 9DR (0202 574252).

(Photograph omitted)