There is something very Alice in Wonderland about the eccentric yew topiary of Crathes. It’s as if these “egg and cup” forms were meant to be precise geometrical shapes but, out of some will of their own, grew distorted. They are also one of the garden marvels of Scotland, dating back to 1702.

It should be no surprise therefore that when the Royal Botanic Garden Edinburgh decide to create a yew hedge, grown and propagated out of collected material from great yews across Scotland, the UK and Europe, it looked to Crathes.

This new hedge, which circles the periphery of the botanic gardens, is a yew library, grown out of 2000 trees collected from 16 countries where they are threatened, and one that comes with stories attached. Some of these are told in a new book, The Yew Hedge, by the project’s creator Martin Gardner. Many cultures have beliefs associated with the yew: the idea, for instance, that planting a yew tree or hedge along the boundary of your property would protect you from evil spirits.

Scotland is home to some significant yews, incorporated now into this hedge, not least the Fortingall yew, the oldest tree in the United Kingdom, estimated to be anything from over two thousand to nine thousand years old. According to a popular legend, Pontius Pilate was born under this tree. Also included in the RBGE hedge is the progeny of the John Knox yew in Renfrewshire under which it is claimed the religious reformer gave his first sermon in 1556.

The hedge’s creator, Martin Gardener, has said, “There is a need to conserve old-growth trees and remnant populations, and to safe-guard plant biodiversity in the face of global environmental change. Once the hedge is established, I look forward to being asked why the yew hedge is not uniform in growth, colour and texture. My response will simply be ‘Ah, but that is biodiversity for you’”.

At Crathes, the hedges, which had become oversized and at risk of collapse, have been recently restored. National Trust for Scotland gardener, Chris Crathes, described the result, “Above all, our ethos is not to re-create the formal straight edges of the Victorian era but to keep the romantic feel of the way we perceive the hedges today. So, they have a character and personality that is fundamentally all Crathes – a little wonky and misshapen, but that this is the consequence of hundreds of years of growth and ageing, just like the rest of the gardens and estate.”