This green and pleasant occupation

When the word therapy is used in a phrase like art therapy we know that we are neither talking about art nor even therapy. However the exception must be made for the national therapy of gardening, celebrated this week at Chelsea, through the summer in numerous smaller fairs and finally in the early autumn with a rush of highly contested local flower and produce shows, where a vase of dahlias or five polished potatoes may carry the fiercest ambitions that an individual experiences all year.

As George Orwell pointed out in 1941 when he was seeking to fix the English character on paper, the love of flowers - more accurately, the love of gardening - is a very distinct part of our national personality which in no way contradicts our otherwise poor performance as artists and our undeveloped aesthetic feelings. Very cleverly he made the connection between gardening and the "addiction to hobbies and spare-time occupations - the privateness of English life", and went on to set it in the context of our mild political life and our hatred of regimentation.

It is probably still true of tens of thousands of Englishmen and women today, that they would prefer to fiddle in their gardens or potter on their allotments than attend a football match or a fashion show or even talk to their neighbours.

Gardening is as much about spending time with yourself as anything else and the unwitting meditative value of a few hours in the garden, even in the dead winter months, when growth seems unimaginable, cannot be overestimated.

A spell living in Manhattan, where there are very few private gardens, was enough to convince me that the problem with New Yorkers was that they spent too little time by themselves and that they had, in the course of an average week, almost no contact with anything natural or that needed tending. It seemed to me that their attention was forced inwards and what they found was always wanting. We are perhaps less self aware and certainly less keen on self-improvement, but that makes us less prone to anxiety.

In New York, there are schemes where you can join a community garden and be allotted a dead-heading or mulching duty, but this is a poor substitute for the beautiful solitude of looking after your own space and delineating it with your taste and effort.

The word garden comes from the old German word gart - or enclosure. We all know that a border is a patch of ground filled with flowers or shrubs, but it also - crucially - marks the beginning and end of territory, the division between your enclosure and someone else's. What goes on in that space is entirely one individual's choosing, except in the rare case of a husband and wife who garden harmoniously together and effectively merge into a single horticultural custodian.

But the therapeutic worth of gardening is not just about guarding the cave entrance. There is a now a great deal of evidence to suggest that association with and nurturing of living things has distinct physiological advantages.

In his book, The Future of Life, the American naturalist and thinker, EO Wilson writes about the benefits of biophilia - the love of the natural world. He cites the example of 120 people who were shown a stressful movie, followed by videotapes of either natural or urban settings. Unsurprisingly they recovered from the feeling of stress more quickly while experiencing natural settings.

Plants and aquaria are said to help people recovering from surgery. Prisoners given window views of forest and farmland suffered far less from stress-related headaches and indigestion. Psychiatric patients responded better

to treatment when surrounded by pictures of natural environments.

One wonders why anyone bothers to study such things because we all instinctively know about the restorative effects of nature, even when considering a clump of prize hostas that have been eaten by slugs.

Gardening is about disappointment and failure, especially when you work against nature and are blind to its requirements. Colour schemes which do not consider soil type, the need for light and shade, or drained ground, never work and should force the gardener to make concessions in his scheme. The best gardeners all realise that the designs that nature dreams up by self- seedings and roses which ramble in unexpected directions - in the case of my garden a William Lobb rose sprawling into a eucalyptus tree - are always the most startling. To become part of this process in a garden is truly the most therapeutic and requires absolutely no effort at all.

Last week I spent a good deal of time crouching on the damp Pyrenean slopes looking at wild flowers, and I was struck by the fact that the natural designs consisting of mountain grasses, primulas, geraniums, gentians and orchids would be far superior to anything dreamed up at Chelsea this week, despite the fashion of the moment for wild gardening. The other point, by the way, is that nature's designs use only five or six elements - never more - which is worth remembering when you are tempted to buy 20 different specimens in a garden centre and plant them altogether in one border.

Cheque-book gardening doesn't work because it goes against nature and the notions of appropriateness which we all have hardwired into our brains. The instant effect achieved by trays of imports robs you of the joy of cultivation, something which has been with us for the last 10,000 years of our history.

So, perhaps the therapy to be had from gardening comes from concentrating on the discreet processes of nature and working with them. As EO Wilson observes: "We need nature ... it offers choices our spirit was designed to enjoy."