Why does the ash tree have black buds? Why does the yew tree live so long? Why does the chestnut tree have white candles? In an imaginative attempt to answer some of these questions, 19 prominent writers, from Kate Mosse and Blake Morrison to Joanne Harris and Philip Hensher, have given their time and contributed original tales to help raise awareness of and funds for the Woodland Trust.

The project is the brainchild of Woodland Trust trustee Jonathan Drori and his wife Tracy Chevalier, bestselling author of Girl With a Pearl Earring and Remarkable Creatures, who has herself written a tale explaining why the birch tree has silver bark.

"The whole thing has been immense fun and I've learnt a lot about trees on the way,' she says. 'There's something about reading all the stories at once that makes you feel like you're in a grove of trees, looking at them as individuals for the first time. Some are traditional fairy tales, some are more off the wall, others have the feel of Greek myths; taken together they not only extend our knowledge of trees but the fable as a literary form."

The tales mainly focus on UK native species, though the trees that have left their mark on Tracy Chevalier stem from her childhood in the USA.

"I vividly remember spending time up in the branches of a beech tree in our Washington back garden," she says.

Other contributors to the book include Ali Smith, Richard Mabey, Maggie O'Farrell, William Fiennes, Rachel Billington and James Robertson. All the authors have had a tree dedicated in their name at Heartwood Forest in Hertfordshire, where for the last few years the Booker judges have symbolically planted trees to represent those felled in order to produce the hundreds of books submitted to the panel.

Watch Tracy Chevalier talking about why she got everyone involved in the project.

Photo gallery from the Why Willows Weep literary event at Windsor Great Park.