I’ve already discussed why you should thin fruit from your tree. Yes, you really should!
I’ll mention one more reason now that I didn’t touch on in the last post: Many young, developing, dwarf fruit trees tend to be precocious. That is, they often start bearing fruit in their second or third year of growth. Naturally, we are all excited to see that fruit! However, allowing it to remain on the tree diverts energy from the tree’s ability to grow a strong branch structure or weights down the leader. As a result the tree often becomes a runt. If you weren’t convinced by my earlier post to thin your fruit, hopefully you will reconsider.
Now on to the how…
- There are 3 ways to exert some control over the amount of blossoms produced:
Annual pruning removes excess branch growth and with it excess buds. When done properly, it also allows light into the tree, which helps with fruit bud initiation, as well as maintaining the health of the tree in many ways.
- Excess fruit can be removed by hand.
- Apples can be thinned using plant hormones, as well as one insecticide that mimics a plant hormone and causes fruit thinning.
Most fruit buds produce from 3 to 6 blossoms in a cluster. The king bloom is the first and central one in the cluster. If you are growing apples, ideally, the goal is to “keep the king.” It typically opens, is pollinated, starts growth first, and results in the largest fruit.
The goal of proper fruit thinning is to balance the number of fruit on a tree with it’s capacity to support them. This is dependent on the number of photosynthesis factories, better know as leaves, the tree has. Depending on the type of fruit, the vigor of the variety, and the health of the tree, it takes anywhere from 30 to 75 leaves to support a fruit that will develop to a diameter of 2 ½ inches or more. Generally this means that you want one fruit for every 6 to 12 inches of branch growth or no more than a single fruit per spur on compact varieties.
You can start hand-thinning when June drop is done or roughly 4 to six weeks after bloom. Best results for creating large fruit are achieved if thinning is completed before the end of July.