Pruning and Root Pruning Apple Trees
Pruning is necessary for training and maintaining the shape of apple trees.
Carefulcan ensure that the branches are well spaced and that the centre of the tree is open so that air and sunlight can penetrate to every part. Pruning can also facilitate the spraying of trees, the picking of the fruit, and can help to ensure that the crop is one of quality rather than of quantity.
A sharp knife makes the cleanest cut, although some secateurs also cut cleanly. A saw will be needed to remove the big branches of old, neglected trees. The teeth of the saw should be set wide apart so that it can cut through the green wood easily. Long-handled pruners are recommended for pruning old standard trees.
Pruning Bush Trees
Prune back the single stem of a one-year-old tree or maiden at a point 2-1/2 ft. abovelevel, making the cut just above an outward-pointing bud at an angle of 45°. Three almost equally strong growths should then develop from the three uppermost buds. Prune these growths back to one-third their size in the following November or December, making the cuts in the same way as before.
The second pruning should produce six or seven shoots. Cut these shoots back by about half in the following winter. Thus six or seven main primary branches will be produced. Once this ‘main head’ of the tree has been formed the tree can be pruned on either the spur system or the regulating system.
By the spur system, the one-year-old side growths (laterals) from the primary branches are pruned back to within 1 in. of their bases, while the end one-year-old growths on every branch, known as leaders, are pruned back to about half. This system of pruning can be continued year after year.
By the regulating system the majority of the one-year-old side growths or laterals are not cut back at all, while the leaders are pruned back only by about a quarter. The unpruned laterals usually produce fruit buds so that in the following winter these side growths can be pruned back to 1 in. above a plump fruit bud. This means that there will be no secondary growth as there is when one-year-old laterals are pruned. If this method is adopted, all the branches that tend to grow into one another as well as those that are rubbing one another are cut away, and the bush is merely thinned out to let in light and air.
Root Pruning Apple Trees
When trees are making nothing but strong wood growth, and are not producing fruit buds, they should be root-pruned, the object of the pruning being to encourage the production of fruit buds. The thick anchorage roots—apples do not have a tap root—must be cut back so that the amount of sap sent up to the branches is reduced and excessive growth is checked.
Root-prune as soon as the leaves have fallen.
If a tree is seven or eight years old and is one that has been grafted on a strong stock and has been pruned hard in the early stages, it is possible to dig it up with all its roots, shorten the roots to half their length, and replant the tree immediately in the same place.
Root-prune older trees in two stages. In the first year dig a trench 2 ft. wide, 2 ft. deep and 3 to 6 ft. or so away from the trunk of the tree (the distance away from the trunk depends on the size of the tree), so the trench extends exactly half-way round the tree on the south side. Cut off with sharp secateurs, or saw off neatly with a U-toothed saw, all the roots that are thus exposed and fill in the trench.
In the second year complete the circle by continuing the trench half-way round the north side of the tree and prune similarly.
The half-circle method prevents the tree suffering too much shock, and ensures that it is not so severely pruned in any one year that it will be in danger of being blown down during winter gales.