T.S.Eliot's Alfred J.Prufrock measured out his life with coffee spoons. I use the changing seasons to measure out mine - starting with the asparagus season, which officially begins in May. As regular readers will know, the arrival of that first bunch of local asparagus is the highlight of my culinary year as it signifies the beginning of al fresco eating and all that's good about the English summer.

This year it was Monday, April 16 (the day after the hottest April weekend ever), when Charles Gee, of Medley Manor Farm Pick Your Own, in Binsey, telephoned to let me know he had gathered the first asparagus and had my bunch ready. It proved as delicious as ever.

Last year, my article on asparagus appeared on Friday, April 21, and was written in anticipation of that call from Charles, which means this year's crop has arrived even earlier than usual. Is this good news or bad news? Should we get excited by the fact that asparagus is now being cropped midway through April?

Well, it's bad news for me if this majestic vegetable, which is usually harvested for just six weeks, is no longer available in mid-June, when I hold my annual rose party. Asparagus spears rolled in wafer-thin slices of bread make the perfect afternoon snack when you are raising a glass of pink champagne to the roses and the English summer. Nothing else works quite as well.

Yes, I could go for smoked salmon or a cold meat of some kind I suppose. But once you create sandwiches out of fish or meat in the middle of June, when the temperature is usually high, you have to be extremely careful how you store the food before the guests' arrival, particularly when every inch of fridge space is taken up with bottles of bubbly and ice. Asparagus is just perfect for summer garden parties.

Many of the Oxfordshire asparagus farmers I've spoken too are unsure how long the crop will last and naturally they worry about that, too. Until recently, the British climate ensured optimum conditions for the cultivation of asparagus in late spring and early summer. As the heat increases, and its season nears its end, asparagus tends to get stringier and tougher, and certainly bears little resemblance to the delicious, plump, green spears that are poking their heads above the ground now.

Despite the fact that asparagus spears are capable of growing several inches in a day when the weather is warm, it is a vegetable that needs at least three years in the ground before farmers can be confident of a decent crop, which calls for a massive investment of waiting time on their part. When it does appear, asparagus has to be harvested by hand. No machine HAS been designed that is capable of carefully selecting and picking the most succulent spears, leaving less mature spears to continue their growth, as the farmer does.

The hands that hold out the bunches with such pride during the brief season have usually been responsible for digging and weeding the asparagus bed throughout the year, too. Then, as the asparagus season gets under way, there is the backbreaking job of harvesting the crop. This is usually done by crawling along the rows, cutting each spear with a sharp knife ready to be weighed into bundles. It's a job usually undertaken in the morning when the dew is still on the ground.

When asked why our farmers don't export their asparagus, members of the British Asparagus Association will smile and say: "We don't export it because it tastes so good we keep it for ourselves."

We are lucky in Oxfordshire. Our soil and climate usually offer perfect conditions for asparagus, which has grown here in profusion since Roman times. Pick-your-owns, such as Rectory Farm, in Stanton St John, actually invite you to pick your own, while others such as Peachcroft Farm, Radley, Q Gardens, Milton Heights, Millets Farm Shop, Frilford, and Medley Manor Farm, Binsey, harvest it themselves on a daily basis.

This means that any bundle of asparagus you buy from your local pick-your-own or farm shop is but a few hours old and can be eaten the very day it was harvested. You can't get much better than that! If you have to store it, wrap it in plastic and place it in the vegetable crisper, but don't leave it there too long. Asparagus should be enjoyed while it's still throbbing with life. The longer you store it the less flavour it will have, which is a jolly good reason for buying local.

If you are tempted to buy a bunch of asparagus that's been imported, sometimes from as far away as Peru, think again. Every time you take imported asparagus home you are not only endorsing that product, rather than the asparagus grown locally, you are missing out on flavour too.

At the time of writing this article, I was informed that asparagus from Peru, rather than local asparagus, was prominently displayed in several Oxfordshire supermarkets. I accept that Peru is of the few countries where high-quality asparagus is produced all year round. Indeed, asparagus is Peru's second most important agricultural export, But it's a product that comes to us bearing a heavy carbon footstep and has been through more hands than can be counted. Besides, it's certainly more than a few days old by the time it's stacked on to the supermarket shelves. (One way to tell its age by the way, is to check the cut at the end of the stalk - if it's reasonably moist then its fresh.) If you buy local, you are sanctioning all that work the British farmer has done throughout the year to bring this mouth-watering product to our plates. By buying imported asparagus you are increasing the chances of global warming and its adverse effect on our own seasonal produce. I know which I'd rather choose every time.

Charles Gee's asparagus from Medley Manor Farm is now on sale, just look for the sign on the Botley Road.