By Marc Carlton and Steve Head
If you read most older books on wildlife gardening you will usually find yourself advised to plant native wildflowers to bring in more wildlife. Here is a typical example:
“A fundamental part of responsible gardening involves planting native species… Birds are far more likely to flock to a garden full of familiar insects and plants, than a garden full of exotic delights” [Birds in Your Garden, RHS/Wildlife Trusts, Think Books 2007]The evidence however is nothing like so clear. Both the terms ‘wild’ and ‘native’, are difficult to define and are controversial; we explain the issues further on our Native or Non-native page, which has a substantial review of the scientific evidence. The Wildlife Gardening Forum is working with the Royal Horticultural Society on what must be the world’s most ambitious and carefully designed experiment to test garden wildlife response to native and non-native species, and you can read more at the page on the Plants for Bugs project
Wildlife needs plants for food and shelter. Plants provide pollen and nectar for pollinators, the adults or larvae of many species feed on live plant tissues or juices, and dead plants are eaten by detritivores. See our page on garden food chains for more on this. The only food form where some native plants are likely to be necessary in this country is the living plant material eaten by caterpillars and other larvae. Many insects do seem specific to one sort of food plant, although many others are much less picky. So native plants will be important for some garden wildlife species, but we still lack proper studies on how garden plants closely related to native plants can also be used.
Many kinds of ‘non-native’ flowers serve this purpose just as well as, or better than, ‘native’ flowers. A more relevant criterion from the insects’ point of view is the accessibility of food. You can find much more on this issue, and pollination in general, on our Plants for Pollinators page.
As we build up more information, we will add material on this website about the native (and non-native substitute) plants that can provide food for caterpillars. Some of these, like Hemp Agrimony are not only good for wildlife, but garden-worthy as well. We hope to be able to suggest lists of native plants that really could help herbivorous garden wildlife, provided of course that the species you are keen to attract do live in your area.
Finally, many wildlife gardeners choose to grow native wildflowers for their intrinsic beauty and interest. At the Wildlife Gardening Forum we applaud their choice, but the message is that if you prefer more conventional planting, you will still enjoy masses of wildlife, and possibly rather more pollinators over the whole flowering season.
You must have noticed that herbaceous borders, herb gardens and cottage gardens can be full of bees, hoverflies and butterflies without recourse to any native species of flowers at all. These pollinating insects have no knowledge of the country of origin of neither the flowers nor whether they are classified as ‘wild’ or ‘cultivated’ plants by gardeners and naturalists. The insects’ priority is simply to find energy-rich, accessible food as quickly and efficiently as possible. Since garden varieties are bred to be smothered with flowers, these can often be preferred to less showy native relatives.
Left: Marc Carlton's pollinator border planted with insect-friendly plants from European origins.