Churchyards have been termed a Noah’s Ark for old, veteran and ancient yews. A valuable refuge that over the years have provided a sanctuary for this historic and culturally significant tree. But there could be a threat to their long-term survival: ivy.
The biodiversity value that ivy in trees provides to all sorts of wildlife is undisputed. From a nectar supply for bees and hoverflies to fruits and nesting habitats for a range of birds.
However, ivy in the crowns of old, veteran and ancient churchyard yews can present significant problems for their long-term survival. Like all trees, yews need a full crown (inner, middle and outer) with a full complement of needles to photosynthesise to support the tree’s energy needs. When ivy begins to spread upwards and outwards within the crowns its swamps these needles, impeding or preventing this vital photosynthesis. The net result is a yew under stress that increases as the ivy increasingly swamps the crown. Given that these valuable yews do not reach great heights they can easily become ivy-clad. Another problem is the ivy on long extending branches that can add considerable weight leading to limb failure: notably in wet, windy weather.
So all is not good with ivy in churchyard yews. And it needs to be managed if these valuable trees are not to be seriously affected.
The solution is to sever the trunk ivy taking out a 3-4cm stem section so the severed stems cannot re-graft. This should be carried out around the trunk base. But if there is concern over low nesting birds, it could be undertaken 1-1.5m off ground: retaining live full-leaf trunk ivy.
Importantly, handsaws should be used to prevent the underlying yew bark from being damaged. If the ivy stems are thick then a wide carpentry chisel using a rubber/wooden mallet could be used – again see bark consideration above. For safety, protective gloves and glasses should be worn.
