Watch Sir David Attenborough in The Green Planet: Human Worlds reveal how humans are helping plants, many of which face extinction. From projects in Africa to re-seeding the landscape to combating miconia in Maui, everyone can work to make our world a little wilder.

Sir David Attenborough explores the hostile world of the desert, where plants can spend decades waiting for rain or travel to find it. Survival tactics include using weapons, camouflage and forming surprising alliances with animals.

Sir David Attenborough reveals the surprising and dramatic effects of the four seasons on plant life. In order to survive the huge challenges each season presents, plants must use strategy, deception and remarkable feats of engineering.