GardenLine | Fruit to Grow and Pick | Pruning Old Apple/Crabapple Trees

1. Thin the outer edges of the tree to allow more sunlight into the center of the tree. Lack of light is one of the main reasons for apples not forming in the centre of the tree. Flowers that will open this spring were actually formed last year. Therefore pruning now will not stimulate flowering this year, but will stimulate flowering next year. Most flowers and thus fruit are formed on short spurs. Do not remove these from the center of the tree, as these are the site of fruit production.

2. Reduce the height of the tree to make picking easier. This does not mean cutting the tree off at the six or eight foot height. "Topping" a tree will only make the problem worse, because this forces dense growth at the top of the tree which prevents any light from entering the center of the tree. Reducing the height, and width, follows the same rules as thinning the outer edges of the tree.

Both the reduction in height/width and thinning are done using a combination of 'removal and 'heading back' cuts. Removal cuts are those that remove entire twigs or branches right at their origin (see diagram). Providing the cut is made close enough to the limb, no re-growth should occur from this point. Removal cuts are most commonly used on older branches, but can very easily be used on last years growth. If the top twigs on the tree grew 12 inches (30 cm) last year, simply cut the top 6 - 9 inches (15 - 23 cm) off. This restricts the height of the tree, allowing it to grow only 3 - 6 inches (7 - 15 cm). Heading back cuts are always made just above a bud(see diagram).

Proper pruning involves removing the 3 D's and 2 C's. In spring you should remove the Dead, Diseased and Damaged branches on the tree. Either type of cut can be used, depending where on the tree the branches are located. Then remove the Cross over and Competing branches. Cross over branches are those that physically rub (or will soon rub). Rubbing leaves an open wound that is more susceptible to moisture loss, and disease and insect entry. Competing branches are those that fill in the same space on three. The more branches on the tree, the more shaded the center of the tree, and the more competition for energy. A tree has only a limited amount of energy to produce fruit. The more fruit the tree produces, the less each fruit receives. The less fruit on the tree, the more each fruit receives, resulting in larger and better quality fruit. removing excess branches will remove excess fruit and thus ensure better quality fruit. Note on the diagram, which branches were removed, and the reason for removing them.

Pruning of fruit trees is best done in early spring. As a resident of Saskatchewan, one can never guarantee that all branches on the tree survive the winter. For this reason, it is recommended to not prune until the buds have expanded on the tree, thus indicating which are alive and which are not. At this time prune out the 3 D's and 2 C's.

One should not remove more than one third of the total growth at one time. Excess pruning will lead to the growth of weak branches, that seldom survive our winters. Minor pruning every spring is highly recommended, as opposed to major pruning every few years.

Pruning is not a complicated process, once you know the basic rules and regulations. Practice makes perfect.

Wood is an instructor with the Department of Horticulture Science. This column is provided as a service by the Extension Division and the Department of Horticulture Science, University of Saskatchewan.

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Sustainable horticultural information, offered free of charge to the public with the support of the University of Saskatchewan Extension Division, the Department of Plant Sciences and the Provincial Government.