If the trees are old and practically perfected in shape, the work of clipping is not such a difficult matter as when the trees are in course of training. But it is usually the case that although many of the trees are old there are young ones coming on that have to be shaped. In the case of old trees, as a general rule, all that is required is to take off the year’s growth; clipping back to the old growth of the previous year.
Hard clipping of old trees is a practice that should to a certain extent be carried out, unless it is desired to enlarge the size of the tree. If this is the case, from one inch and a half to two inches of the year’s growth should be left on, but not more.
Altering the shape of old trees is a thing that should be avoided as far as possible, especially if the trees are well shaped and in a healthy condition. It sometimes happens that one or more trees in the garden may have been allowed through careless management or some other cause to grow out of shape; or perhaps an old tree may be obscuring the view in some way or other. In the case of such a thing happening, it will be necessary to use the pruning knife or saw rather severely, both of which can be used with perfect safety when they are in the hands of a person who thoroughly understands the yew; provided, of course, he does not go to extremes, the yew is a tree that will stand a fair amount of rough treatment, and one that can be twisted and cut into almost any shape desired.
I have seen old specimen trees that had grown out of shape, or were, perhaps, shutting out the view in some part of the garden, taken down and re-trained, or cut down with the pruning saw, or knife, as the case might be; and yet in a very few years they had quite recovered and grown into nice, well shaped trees, full of vigour and well furnished with young growth. Rather will the tree, if it is carefully managed, be improved by the severe pruning it has been subjected to.
Of course, after an operation like the one I am describing, great care will have to be taken that every use is made of the young growth, as the main object to be kept in view is to get the tree well furnished again in as little time as possible. There will be very little, if any need for using the shears the first year after the cutting back has been done; but if the young growth is at all rank, it should be carefully thinned with an ordinary pruning knife, always taking care that only the weaker shoots are removed, leaving the stronger ones to grow for use another year, when they can be tied in and cover up, as far as possible, the old and bare wood. When tying young shoots, tarred string will be found most suitable. It answers the purpose very well and it is easier to tie than wire, although it has a tendency to decay quickly through being always exposed to the weather. In the case of young shoots the pressure is not great and string will generally last as long as the tie is required, as the shoots soon become matted and interwoven together; but if a strong branch should happen to get displaced in any way, the use of string as a tying material should be avoided and copper wire should always be substituted in its place. In the case of an old branch the pressure is greater, and whatever material has been used in the work, it will as a rule be intended to last for years. For the purpose of tree tying of any description copper wire is to be recommended; it has not the same injurious effect on the trees as ordinary galvanised wire; but whatever is used, cork should always be placed between the wire and the wood as a preventive against cutting the tree.