The subject of our meeting on 17th April was The Art of Tree Moving. The speaker was Deric Newman who is the General Manager of Civic Trees a company which specialises in moving mature trees. The scale of their activities, the size of trees moved and the size, power and complexity of the machinery employed are mind-boggling; a very different matter from the domestic scale of the horticulture we are normally concerned with at our meetings. Deric’s beautifully illustrated presentation was lively and entertaining and held the attention of a well-attended meeting …
Deric began by setting out the reasons for moving mature trees. Trees can be moved when they might otherwise be felled, to create space on a development, to improve the location of a tree or to use the tree for a different purpose, perhaps to use it as a new focal point. Deric followed this introduction by a brief survey of the history of tree moving. If the Hanging Gardens of Babylon existed it is thought mature trees would have been used. In the seventeenth century the landscape gardener Andre le Notre moved trees from the Bois de Boulogne to the grounds of the palace of Versailles and tree moving was sufficiently common to justify the publication of a book on the subject by John Evelyn. In the eighteenth century Capability Brown and Humphrey Repton frequently used mature trees to create their landscapes.
The modern history of mature tree moving began in the massive urban regeneration of Britain in the post-war years of the sixties. With government backing, the Civic Trust was formed to promote the use of trees and Deric’s father worked closely with the Trust in carrying out this work. Initially most of the work involved the removal of forest trees because there was very little provision for commercially grown trees. Deric’s father was much involved in the development of techniques for tree moving and a very significant development was his invention of the Newman Frame which allows a root ball of between 2.5 and 4.5 metre diameter to be lifted. It is still the most effective and efficient way of moving large trees. When the Civic Trust closed in 1963, Deric’s father took over its work and set up the company Civic Trees which Deric now runs.
The process of moving a large tree may be spread over a couple of years, although development requirements often don’t allow this sort of time. Preparation involves root inspection to discover the existing root structure and its extent and determine the future root ball size and relocate any services which might be in the way. The roots are then severed around the tree to a depth of 300 to 750 millimetres and a barrier put round them to prevent root regrowth. The rootball is wrapped in hessian attached to the frame and it is never undercut; the whole tree being lifted from the remaining roots by brute force. As well as root severance the crown of a large tree may be removed to reduce stress on regrowth.
A standard formula is used to determine the size of the rootball that will be necessary for good regrowth and this can be used on a domestic scale for moving small trees and shrubs in our gardens. The diameter of the rootball should be three times the stem diameter at a height of one metre above ground level.
When a tree is ready to be lifted a two inch hole is drilled through the trunk and a bar inserted and attached to the frame so that the weight of the tree is transferred to the frame. Before removal a new hole of carefully measured depth will have been prepared and made ready to fill with good backfill material of a high organic content which will include root builder and fertiliser. After transfer the tree will be guyed with wires to prevent movement while new roots are being established. The tree will suffer transfer shock after replanting and this will stop any growth in the first year with slower than normal growth in roots and foliage the next year. Maintenance will be needed for at least a couple of years. This involves lots of water, applied infrequently, further pruning, an annual feed, mulching over the rootball area with bark and checking the guy wires to maintain tension.
Instead of a frame over the rootball a different technique is used for smaller trees. This is a mechanical ‘spade’ fitted on a powerful tractor. The spade consists of four curved blades which wrap round the tree and then dig round it and under it; the four blades fitting together around and under the tree so that it is removed with no need to wrap the rootball and driven to the new site. A matching hole will have been prepared with the use of the same sized spade. In 1968 Civic Trees imported the first ‘tree spade’ to be used in the UK.
Nowadays there are many nurseries growing mature trees commercially. Civic Trees take clients on nursery tours to choose their trees and Deric told us that Deepdale Nursery near Potton is an interesting place to visit. A selection of photos, courtesy of Civic Trees:
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Our next meeting will be on 15 May when we shall have a talk on Warden Abbey vineyard with wine tasting and sales.