Victoria Summerley: Town Life

"Loveliest of trees, the cherry now/Is hung with bloom along the bough, /And stands about the woodland ride/Wearing white for Eastertide."

A quintessentially English scene, described by a quintessentially English poet, A E Housman. When he wasn't penning the odd iambic tetrameter, Housman edited the works of the Latin poets, so his pedantic soul would probably have rejoiced at the current debate going on within smart horticultural circles about native plants versus exotic interlopers.

The argument goes like this. Too many of us are growing alien species such as phormiums, cordylines, fancy conifers and yellow-leaved trees such as Robinia pseudacacia 'Frisia', which, says garden writer and designer Noel Kingsbury, in the RHS journal The Garden, clash with native plants and look out of place.

He comments: "Do we want gardens throughout the country to look the same, with no sense of regional diversity? If everyone grows yuccas and phormiums in their front garden, aren't we in danger of suburbanising the whole country?"

Mr Kingsbury is someone for whom I have a great deal of respect and I applaud him for raising the issue of what he calls "visual ecology". But on looking around my particular urban environment, I would be hard-pressed to find any native species. If it wasn't for the exotica, there would be hardly any greenery at all.

Even those staples of springtime that we all take for granted - magnolias, camellias, cherries - are foreign migrants, brought back by intrepid plant hunters to be pressed into service in millions of British gardens.

Britain has always had the native wild cherry, Prunus avium (the sort A E Housman was talking about), but the ornamental sort that unfurl their thousands of mini pink tutus at this time of year are Japanese, many of which only started to be introduced to this country around the time of Housman's death in 1936. The cherry plums, which tend to have darker leaves and smaller pale pink flowers, are from Iran.

Wisteria comes from China and Japan. So do camellias. Forsythia, whose chrome-yellow flowers play a starring role in suburban spring displays, is an Asian immigrant too, named after William Forsyth, the Scottish botanist who was a founding member of the Royal Horticultural Society.

It's not just spring flowering plants. We tend to think of a rose garden as a typically English phenomenon, and it's true that many of the roses in it might well be grown on the rootstock of the native dog rose, Rosa canina. But their multi-petalled flowers and their heady fragrance owe their existence to horticultural experts who lived thousands of years ago in Babylonia, Assyria and China.

The reason all these plants became popular in Britain is because they suited our temperate climate. In fact, that's why plant hunters like Collingwood "Cherry" Ingram (who was responsible for introducing many of the ornamental Japanese cherry cultivars), brought them back here in the first place. They didn't go off to China and Japan by accident, they made a beeline for regions which had a similar climate, specifically to look for plants that would do well in the UK.

Why is it all right to have plants that were introduced a century ago from Asia but not plants that were introduced 50 or 30 years ago from the Antipodes or South America? At a time when hosepipe bans are in force in the South-east, and our summers are getting drier and hotter, it makes sense to look for plants that will cope well with drought. And if that means choosing varieties that are non-native, then that is simply continuing a tradition that has been going on for hundreds of years.

If you have a hot, dry, dusty London backyard, it makes more sense to grow a yucca - which likes desert conditions - than, say, a primrose, which prefers a cool, moist situation.

If we really want to preserve the lush meadows and verdant woodlands of the English countryside - not to mention Mr Housman's wild cherry trees - let's save water where we can in town.