You may well be thinking that life is too short to spend time in the orchard thinning fruit. In our view, any time spent in an orchard is a bonus. There are, though, some good reasons to thin fruit particularly if your trees are heavy croppers. The main one is that the tree will produce better quality and size fruit – albeit fewer of them – but there are other benefits
- heavy crops can cause limb damage
- fruit will ripen more evenly as more light and air can penetrate the branches
- it may help reduce the spread of pests and diseases
- heavy cropping in young trees can set them back
After the tree has finished blossoming small fruits begin to form from the flowers that were successfully pollinated. Crop size varies from year to year but if it is a bountiful year thinning out some of the fruit from each cluster enables the tree to direct its resources to the remaining apples.
A few weeks after the fruit has set, the tree will often shed fruit naturally. This is known as the ‘June Drop’
(although it doesn’t always happen in June and can go until July in some areas). It is wise to wait to until the full extent of the natural loss of fruit is known before you start thinning fruit yourself.
Fruit thinning should be done when the immature fruits are roughly the size of a thumbnail. At this point in their development cell division is still taking place, so if some of the apples are removed the extra nutrients at the tree’s disposal will be channelled into the remaining fruit throughout summer resulting in larger, healthier apples.
If several apples have been produced on each bloom cluster, thin to one or two fruit. First, remove any that are damaged, diseased or poorly positioned, i.e., shaded by the other fruit or leaves. Opinion is divided on whether the centre fruit, or ‘king’ fruit, which tends to be larger should be left or removed. One view is that the flesh of the king fruit is coarser and doesn’t store as well. Others believe it is the best candidate to develop into the largest, juiciest fruit. Either way, the aim is to leave a couple of the best formed and healthiest looking fruit.
Use clean, sharp secateurs or scissors to thin excess fruit rather than plucking with your fingers, as sometimes this can weaken the base of the cluster causing the other fruit to drop.
If an apple tree has developed a two-year fruiting cycle – biennial bearing
– thinning the fruit in the year when it is cropping can sometimes help correct the problem. However, it is normally more effective to thin the flower buds before the fruit has started to develop leaving enough resources for the formation of fruit buds the following year.