Recently the results of a study of gardens and their benefit for wildlife, conducted by Ken Thomson and his colleagues at Sheffield University, have been published in a lovely little book that every gardener should read. Basically the study has revealed that any garden is good for wildlife. Size makes no significant difference, but there are some cheap and easy things the gardener can do to improve the benefits their garden provides for wildlife. Significantly, some of the things that are recommended in every other wildlife gardening book have been shown pretty conclusively not to work, and worse, to be a waste of money.
Based on the facts revealed by the study and my own experience, here are my top tips for wildlife gardening:
1) Anyone with a garden or outdoor space (balcony, patio, roof) can garden with wildlife in mind, so long as they have some plants and ideally some water as well. The bottom line is that any plants are better than none and the water can be as little as a shallow bowl 20cm in diameter.
2) The bigger the bulk of plant material ie the more plants, the better. Wildlife does not seem to care if the plants are native, but it does care that the plants provide shelter or nectar. To this end, try to provide one or two plants that are evergreen and will provide dense humid cover eg ivy, bay, aucuba (although if you have any pretentions to aesthetic taste, not the nasty thing known as spotted laurel). Also leave some tall hollow dead stems in place over winter eg teazel, hemlock. Concentrate on simple single flowered plant varieties, as double flowered varieties have sacrificed nectar for the extra petals. If at all possible have a tree even if small, and if that is not possible, try for a sizeable shrub.
3) Make sure your idea of wildlife is realistic. In Britain, wildlife in gardens mostly means invertebrates and birds. If you get mammals and amphibians that is a bonus.
4) Don't own a cat and discourage your neighbours' cats vigorously. There is nothing more disturbing than the close proximity of a cat to a lot of wildlife.
5) Do not use pesticides or herbicides of any description. Within 2-3 years an organic garden will establish a microclimate and reach an equilibrium. My garden has some aphids (rarely enough to cause me any distress or ruin any plants) and as a consequence, it also has hoverflies, ladybirds and Blue Tits energetically predating the aphids. (I would also suggest you do not use soapy water to control aphids either, as in my experience it is almost impossible not to damage plant leaves because the detergent is too strong.) My garden has snails, and every few years, it is true, my hostas and acanthus get turned to lace, but the compensation is that I have two sorts of thrush who come in and bash snails on the path just outside the back door. I help to keep the population of slugs and snails low by growing my plants hard ie they do not get much fertilizer or water, and as a consequence do not tend to put on large quantities of delicious sappy new growth. (Remember, too, that slugs and snails are wildlife, and that many of them do not eat fresh plant material at all, but decaying plant material.) I have given up trying to grow delphiniums though. The only pest I take action against is Vine Weevil, and I do this by dosing the garden with a biological control, a nematode that is a parasitoid of the weevil larvae. Vine Weevil is the only problem my garden ever has particularly badly and this is because my whole garden is contained in pots, but the nematode is spectacularly effective. Even so, I have given up wasting my money on fancy varieties of primula and heucera, as they are so prone to Vine Weevil attack.
6) Have a pile of rotting wood hidden away in a corner – this can be as small or as large as the garden has space for. Ideally, also have some tall standing dead wood. Remember that a dead fruit tree will provide a fabulous climbing frame for a rambling rose, and if you chose a single flowered variety it will be smothered in pollen collecting insects as well as providing a nursery for the likes of stag and longicorn beetles. Also a rambling rose will completely cover a dead tree in a couple of years and prevent any problems of hazardous falling branches. Once a vigorous rose has a hold, any falls will be contained in the tangle of rose stems. Cheaper and prettier than getting the tree surgeon in.
7) If at all possible have an area of long grass. You can dress it up as a wildflower meadow if you need a further excuse not to mow, but frankly, what your wildlife will be interested in is the rank grass.
I have a tiny garden, about 5 x 6 metres, situated on the eastern outskirts of London. Not only is the garden small, but it is surrounded by walls 2 or 3 metres high and all the plants are in pots. When we first moved to this house, 9 years ago, the garden was an ugly, empty courtyard, paved with asphalt. It is now crammed full of as many plants as I can fit in and still move around the garden, and the asphalt has been dug up and replaced by gravel and reclaimed York stone. There was no point trying to grow a lawn, as only about a fifth of the garden gets any direct sun.
So there are some things that I just cannot grow in my garden, and in a garden that has its roots entirely contained, I struggle to get much height out of plants. I have erected trellis and clematis and some roses perform fairly satisfactorily, providing dense vertical cover, but honeysuckle is more like honeysulky. Ivy has no problem with this situation though – to the extent that it has now climbed up the building next door and is making the garden even more shady. It has really become a bit of a dilemma – to give it the chop or not? – an agonising decision.
I am lucky in some respects though. The garden next door is large and abandoned, with many very mature trees. A lot of these trees are narled and pretty manky looking, but they include many different varieties – so much so that I think someone in the 19th century was creating a private arboretum – and because they are largely undisturbed (except by teenagers seeking a place to set off their fireworks), they are ideal habitat for wildlife. As Ken Thomson points out in his wonderful little book 'No Nettles Required', wildlife doesn't see garden boundaries – as far as it is concerned, rows of gardens are just another 'wildlife corridor'.
For such a tiny garden, I get a very satisfactory number of visits by birds and invertebrates. I once had a frog, but of course, with high solid brick walls, I cannot expect to get mammals (except rats and mice, who cheerfully chew through the wooden garden door to get to the bird food on the ground).
Because the garden is so shady, my aim is primarily to provide shelter rather than the more traditional approach of providing a banquet of nectar plants. Quite a few of my plants will flower and that is a bonus, but the important thing is sheer bulk of plant material, providing dark humid places to hide as well as the occasional solitary tall plant like teazel or a small hazel tree to sit on and look out for prey or warm the flight muscles. The single most important addition to the garden has been a shallow tray of water. It is in fact the bottom of a hamster tray, tastefully disguised with rocks, gravel, and ferns. As soon as it was installed there was a noticeable jump in the numbers of birds coming to the garden. Over the years, as the plants have bulked up, and created their own microclimate, the variety of invertebrates has steadily increased too.
As an indication of the success of the garden, note that I have recorded the following species of butterfly in the garden. Bear in mind that the garden is shady and not focused on nectar plants, but even so, I get virtually every butterfly one could hope to in a London garden.
Butterfly List for the garden:
Clouded Yellow Colias croceus
Brimstone Gonepteryx rhamni
Large White Pieris brassicae
Small White P rapae
Green-veined White P napi
Orange-tip Anthocharis cardamines
Holly Blue Celastrina argiolus
Red Admiral Vaness atalanta
Peacock Inachis io
Comma Polygonia c-album
Speckled Wood Parage aegeria
Gatekeeper Pyronia tithonus
Thomson, K. No Nettles Required: the reasurring truth about wildlife gardening. Eden Books. Transworld. 2006.
What we started with (actually a shot of the garden emptied in January 2003 as preparation for digging up the asphalt and replacing it with gravel and York stone).
The garden in April 2001, three and a half years after we moved.
What the garden looked like in May 2006, after 8 and a half years.