Warren Farm is home to Britain’s smallest butterfly, the Small Blue. The Small Blue has suffered years of decline and it now occurs on less than 15 sites along the North Downs.
The Small Blue needs the Kidney Vetch in order to survive. The females lay their eggs on the buds and flowers of Kidney Vetch, which act as food for their larvae.
As volunteers pull out the invasive Canadian Golden rod, it creates bare ground on which the Kidney Vetch seedlings can become established.
The very first Small Blue was found in 1995, the population is now positively thriving. The removal of Goldenrod, by hand has undoubtably been the key to this success, as it allows the kidney vetch to thrive.