Washington's Siamese holly trees

In the last of his current series celebrating Clever Trees Richard Uridge visits the National Arboretum at Westonbirt in Gloucestershire, England – with 18,000 specimens a veritable tree university – and talks to the trees.

In the penultimate programme of his five part series on Clever Trees, Richard Uridge finds a headache-inducing specimen in the Lost Gardens of Heligan.

In the the third of his series on arboreal intelligence Richard Uridge travels to tropical Far North Queensland in Australia to meet a tree that can, it's claimed, create its own rainfall.

Richard Uridge travels to George Washington's home at Mount Vernon in America to meet two holly trees conjoined at the trunk. The first in a series of five podcasts from around the world.

In the second of his series on arboreal intelligence Richard Uridge travels to the Malaysian jungle in search of a tree so clever it can tell the time. Or at least that's the theory. Armed with a wristwatch he puts it to the test.