BBC: Plants have never been as important to the environment, the director of Kew Gardens has said, ahead of the London conservation site’s 250th anniversary. They were vital to reduce the impact of climate change and “vast numbers of humans” needed them for medicine and food, Professor Stephen Hopper added. Several major events will be held in 2009 to celebrate Kew’s role as a world leader in plant science. The first of these sees free public entry to the gardens on New …