4 MARCH 2006, Page 54

Exploding myths

Ursula Buchan

Ihave been talking tosh. Well, not entire tosh, but certainly substantial dollops of wishful thinking and airy, groundless supposition. I have come to this conclusion after reading a book by a plant scientist called Ken Thompson. However, it is written in such an engaging, amiable and witty way that it doesn’t hurt too much; especially since I can console myself that almost everybody else has been as deluded as me.

Ever since Ken Thompson’s first book — An Ear to the Ground; Garden Science for Ordinary Mortals — was published in 2003, I have been a big fan. He is a senior lecturer in the Department of Animal and Plant Sciences at the University of Sheffield, who left his academic papers briefly to attempt to teach gardeners horticultural science in a way that they could understand without feeling patronised. As I read it, I could hear the deafening boom and crump of exploding myths. With his second book, No Nettles Required; The Reassuring Truth about Wildlife Gardening (Eden Project Books, £10), he is at it again, trying to make us understand garden wildlife and its requirements, using verifiable scientific information. Crump, boom, aaaargh.

Ken Thompson was a key instigator of the first biodiversity survey of urban, private gardens (Bugs), begun in Sheffield in 2000. The aim of this survey was to discover what there really was in the way of wildlife in the average garden; not large rural gardens, where people mostly think the wildlife is, but small or smallish urban gardens, of various ages and gardening regimes. They chose 61, and set up a number of facilities for collecting small wildlife in them, including pitfall traps (for ground-living creatures) and Malaise traps (to capture flying insects).

This project must have been frustrating at times, since money was plainly tight. Sadly, moths were not counted, since the scientists could not depend on anyone getting up before dawn to empty moth traps, and neither were butterflies, since that requires people to run around catching them in nets. Quite often, therefore, Thompson himself bumps up against lack of data, and is not above the odd airy sup position. Nevertheless, Bugs found out a great deal that was not known before, and the results are not only interesting, but also hugely cheering. In a nutshell, gardens are wildlife havens, often much more plentiful than the (agricultural) countryside. And large gardens are not qualitatively better than small ones.

As well as the data from the Bugs survey, Ken Thompson could also draw on the remarkable findings made by Jennifer Owen from 1972, in her suburban garden in Leicester, collated and published as The Ecology of a Garden: The First Fifteen Years (CUP, 1991). Dr Owen meticulously monitored wildlife of every kind in her garden over many years and concluded that, over time, more than 8,000 species of insect resided there, together with many other sundry invertebrates, such as millipedes and spiders. This included some species new to science. Of course, we ordinary gardeners haven’t a hope of telling a Gasteruptid from an Ichneumon wasp, but it is encouraging to think how rich a world there is, unseen but right under our noses.

Moreover, to promote the interests of wildlife, we apparently need to do little that is onerous. Simply by refusing to use pesticides, particularly insecticides and slug pellets, growing plants with single, nectar-rich flowers as well as trees and shrubs, leaving dead wood around, making compost, not tidying up too much in autumn, digging a pond and letting some grass grow long we can make a good situation even better. Thompson should earn the gratitude of millions of conscientious wildlife gardeners for telling us that we don’t need to grow a nettle patch for butterfly larvae, since nettles are probably Britain’s commonest wild plant anyway.

And what was the tosh I was talking? I believed that it was necessary for many plants and insects to have co-evolved if those insects were to find plants for their larvae to feed on. In other words, it was necessary to grow a larger number of native plants. The evidence is simply not there, according to Thompson; only a comparatively few insects are really picky where they lay their eggs. For a kick-off, our flora (and fauna, come to that) is almost identical to, if much poorer than, that of Continental Europe, since we were separated only 10,000 years ago, a blink of the eye in evolutionary terms. And it is very similar to the northern temperate flora of the US, Japan and China; the countries where most of our garden plants originate. So, gardeners have carte blanche to grow as many foreign plants as they like.

Thompson would have us alter our mindset, however, if we are to understand the wildlife in our gardens better, and get more fun out of studying it. In other words, we should stop concentrating on a few large animals, such as foxes, which may pass through occasionally, and learn to respect, and foster if we can, the many thousands of creepy-crawly species on whom all those larger animals depend, and for whom the garden really is home, sweet home.