Gardeners should switch from exotic plants back to British to help wildlife, the Royal Horticultural Society has advised, following a landmark four year experiment.

In 2012, experts at the RHS filled 36 plots of land in Wisley, Surrey, with 14 different species from either Britain, the northern hemisphere or the southern hemisphere.

The plots were then tended like a normal garden for 48 months to see which insects moved in. It is the first research project to test whether the geographical origin of garden plants affect the amount and different types of insects and spiders they support.

The experiment showed that insects were more than three times as likely to choose plots with native British plants than exotic species. Out of the 22,000 bugs collected from the patches, 56 per cent of all invertebrates were found in the native ‘gardens’ compared to 26 per cent in the near-native plots, and just 19 per cent choosing the more exotic varieties.