27 JANUARY 1996, Page 42

Gardens

Whither the weather?

Ursula Buchan

We live in a golden age. Even I, by nature pessimistic, am forced to admit it. Never have so many people gardened with such success, using a greater variety of plants, or had more gardens to visit and admire. The amount of information readily available far outweighs any shortfall result- ing from the decline in oral tradition. In short, we know a great deal and we have bags of money and leisure to pursue our interest. The only maggots in the apple are the limited size of many gardens and the cost and unavailability of labour.

Good pessimist that I am, however, I cannot resist pointing out another difficul- ty: the minute, but significant, shift in the climate. Although annual rainfall has, apparently, remained remarkably constant in the last 300 years, winters have lately become perceptibly wetter while summers are drier. Moreover, although tempera- tures in the growing season have remained the same, winter values have risen by one whole degree Celsius. Which is a lot. (I am indebted for this information to an article by Bill Burroughs, an atmospheric physi- cist, in January's Journal of the Royal Horti- cultural Society.) Of course, most gardeners cannot take such a long view as atmospheric physicists. A relatively stable climate, viewed in the long term, still allows for considerable annual variations and it is these which influence the way we look at things. They sometimes cause us to jump to groundless conclusions. We view them too readily as trends. Last summer seemed to us then, and was, exceptional, yet there is now a widely held belief that next summer will be similar. On what basis?

If we experience one harsh winter, we fatally lose our confidence in planting half- hardy plants. I know people who won't grow ceanothus any more because they lost them in the hard winter of 1981/82. Cean- othus are not long-lived in any event, and one planted in 1983 would probably have died of natural causes by now. A whole ceanothus lifetime has been lost by timidity.

We must cease relying entirely on our own experience and pay more heed to the measured conclusions of meteorologists. In gardening terms, the fact that winters are tending to be more humid is more impor- tant than that summers are drier. We can lay moisture-retentive mulches to help thirsty plants through short-lived summer droughts easily enough anyway; it is more difficult, but necessary, to provide a free- draining soil to help nurse, for example, drought-tolerant Mediterranean plants through our wet winters. Changing a soil is harder work than mulching one.

Another consequence of mild, wet win- ters is that deciduous plants break into bud before it is sensible for them to do so. The chief enemy of promise last season turned out to be that sharp, late frost in mid-April, when young growth was already much advanced. The second whammy was deliv- ered by very hot weather following only three months later. Late frosts can make fools even of plants which we normally consider bone-hardy.

There is layer upon layer of meaning in the word 'hardy'. We generally give the title to those plants capable of surviving sub-zero temperatures in winter, but that seems too wide a definition to me. By that token, most hydrangeas are hardy, yet a spring frost can burn their buds and under- mine their flowering. Most of us are nei- ther by inclination or circumstance mollycoddlers of hardy plants. If they are labelled 'tender', we take care to put them in a greenhouse or conservatory. If they are labelled 'hardy', however, we expect them to get on with life without much help from us.

Surely that attitude has to be modified. We must accept the need to protect any slightly dodgy plants in winter, especially those against walls which will, by virtue of their position, always be more forward. We must also take care with the siting of even hardy plants. East walls which catch the sun first on frosty mornings will shatter the cell structure of many plants, which can cheerfully endure any number of cold nights.

We should also look to take fuller advan- tage of plants from countries with climates similar to the one which we now enjoy: the coasts of New Zealand and Australia, and the eastern seaboard of America, and high altitudes in hotter countries.

Of course, many of the plants readily available in this country have a wide toler- ance of climatic conditions. No plant which becomes universally popular, after all, will do so if not universally amenable. So, while enthusiasts like me experiment with hibis- cus and agapanthus, the rest of the world happily continues to grow cotoneaster and potentilla, philadelphus and holly, hardy geraniums and aquilegia, secure in the knowledge that neither wet warm winters nor hot dry summers will do for them com- pletely.