Common name - Ring-barking or girdling
Plants affected - Trees and shrubs
Main symptoms - Loss of bark at the base of trees, occasionally on higher limbs
Main causes/caused by - Careless use of machinery close to trees and animals such as grey squirrels, horses, deer, hares, rabbits and voles gnawing on the bark
Timing - Mammal damage occurs mostly during severe weather but also on newly planted trees
Ring-barking or girdling are terms used to describe the complete or nearly complete loss of bark from around the circumference of a tree or shrub鈥檚 limb or trunk. This disrupts the movement of water and nutrients between the roots and the top growth (sap flow). If untreated it can result in dieback or death of the affected plant.
There are three main causes of ring-barking;
Deliberate ring-barking: Ring-barking is sometimes used as a technique for killing off unwanted vegetation. However, it is not a recommended practise in most horticultural circumstances as this may provide a source for honey fungus infection and is unsightly. Partial ring-barking or 鈥榬inging鈥� is also used in fruit production to reduce shoot vigour and promote fruitfulness but again is not advised for home gardeners as it can, if not done properly, lead to the loss of the tree.
Bark is removed partially or completely at or above ground level exposing the paler inner wood. This can be accompanied by withering, dieback and death of the tree though recently damaged trees and those in a dormant state may not show symptoms initially.
The feeding pattern of mammals on trees is often distinctive; depending on their size and teeth pattern. For more detailed information see the Forestry Commission leaflet on .
In cases where the bark has been damaged but some or all of the cambium and phloem remains, the tree may make a natural recovery. If in doubt, however, attempt repair.
Repair the damage whist still fresh for the best results. Retain as much of the remaining bark as possible to help the movement of sap and encourage healing.
Step-by-step
Step 1: Pare the rough edges away with a sharp knife.
Step 2: Cover the area with a 4cm deep layer of damp moss.
Step 3: Wrap with polythene and hold in place with waterproof adhesive tape. The polythene should be wide enough to completely cover the area and prevent the moss drying out.
You can re-use clean, empty compost bags or food packaging instead of buying new polythene and you can also re-use old horticultural polythene rather than throwing it away.
Step 4: Leave the patch in place until the end of the growing season i.e. at least three to four months to allow the damaged to heal.
Step 5: Check the ties periodically to ensure there is no serious constriction to the trunk and loosened if necessary.
Step 6: Ensure adequate soil moisture by watering during hot, dry periods in spring and summer.
Initially the moss and polythene can be applied as for partially-girdled trees but if all or nearly all the bark is gone some form of grafting will be necessary. Grafting is normally carried out in spring when the cambium is particularly active and the bark is "lifting" easily.
There are two methods of repairing a girdled tree:
For full and illustrated descriptions of the above grafts, please refer to The Grafter鈥檚 Handbook by R J Garner (revised and updated edition 2013) ISBN: 9781845337544, and in particular Chapter VIII Grafting established trees, section 鈥淭o repair and improve鈥�. There are also resources available online.
