Thoughts on Pruning

Pruning apple trees is all about sunlight – shaping the tree to expose all of the wood to enough sunlight to produce strong fruitful spurs, which will set as many seeds as possible, to produce large, well- shaped and wellcoloured apples. A Christmas tree shape is best to achieve this goal, narrow at the top and slightly wider at the bottom. As a tree ages, it tends to reverse this shape, growing strong wood at the top, which shades out the bottom. Removing entire upper branches instead of making many small cuts allows sunlight to thelower areas of the tree.

Pruning apple trees is also about balance. Each tree needs to grow enough new wood each year to renew the fruiting spurs, but excessive growth reduces fruiting and fruit quality. The trend is to let apple trees grow taller, without pruning the leader, and allowing the weight of fruit on the leader to slow the upward growth down, and gradually bendover. Trees that are allowed to grow like this tend to grow more fruiting wood and require less pruning.

Pruning apple trees is about moderation. Annual moderate pruning is much preferable to pruning more severely every 2 to 3 years. Removing a few large branches each year may seem drastic, but after several years, the tree will be calmer and produce fewer strong branches. There should be a good reason to make each pruning cut. Remember that leaves are the food-manufacturing organs, and if the leaf area is reduced unnecessarily, the tree will be reduced in growth and/or fruitfulness.

Pruning apple trees is about dwarfing the tree, and about local response. We know that each pruning cut will dwarf a tree – a pruned tree is always smaller than an unpruned tree – but we also know that each pruning cut will stimulate growth in the local area. Prune that part of the tree where more growth is required, particularly in older trees. New growth will be stimulated only in those parts of the tree that were pruned. Where growth is excessive, reduce pruning to an absolute minimum.

Pruning young apples trees will delay fruiting. In most cases, a good nursery tree needs to be trained rather than pruned, and many growers are seeing the benefit of tying branches rather than pruning. However, any side branch that is larger than 50% of the main leader should always be removed on young trees – this restores the balance in the tree.

These are basic principles of pruning – sunlight, balance, moderation, branch removal, dwarfing and local response. A good pruner needs to keep these principles in mind to make the important pruning decisions that will influence this year’s crop – and for years to come.