Bracken is a fern that spreads by underground 'rhizomes' gradually increasing in area every year. It shades out other species and becomes a dense monoculture that compromises the wildlife value of the park. Left unchecked, bracken would take over the parks grassland by about 1-2 hectares a year.
Starting in July, Richmond Park's Shire horse team roll large areas of bracken to crush the stems and weaken the plant. Over time the bracken becomes increasing small and space and grassland is re-created.
This year contractors will also be controlling bracken by herbicide in areas that are more difficult for the horses to work. The herbicide used only effects ferns and is not harmful to people or animal. The work is being part-funded and approved by Natural England (the Government Agency for wildlife conservation).