Why native plants?

At the heart of my approach to wildlife gardening is encouraging native plants, as opposed to the hybrids and imported (alien) species that are so often found in garden centres. Many of the plants that I actively encourage would be classified as weeds by some other gardeners, yet given the opportunity to flourish, native plants can be just as attractive as over-priced commercially produced hybrids. I think the sea of pink flowers produced by Herb Robert, as shown below, proves my point.

The reason for this focus on native plants basically comes down to evolution. For thousands of years our native plants and animals have evolved together within their ecosystems. In doing so they have built complex interrelationships and inter-dependencies that make the whole ecosystem work.

For example, there are species of native flowering plants that have evolved flower shapes to encourage particular types of insect to visit them, subsequently carrying their pollen to flowers on other plants of the same species. A great example of the interrelationship between flowers and insects is the way that the flower of the white dead nettle is such a perfect fit for the body of a bee, as shown in the picture below.

There are other important relationships too. The spectacular Peacock butterfly lays its eggs on stinging nettles so while I spend a lot of time pulling up stinging nettles in some areas (being careful not to confuse them with white dead nettles) I allow them to thrive in others, and have regular visits from Peacock butterflies as a result. In fact, stinging nettles support over 40 species of insect.

Another point is that the nectar and pollen of native plants can often have a higher nutritional value than that of hybrids or aliens. For example, hybridisation to change a flower’s shape or colour can also have an impact on its usefulness to animals that pollinate it or feed on it.

It's not that I'm totally opposed to hybrids and aliens, there are examples of both in the garden. It's just that I don't allow them to dominate the garden at the expense of the native species.