How to Thin a Fruit Tree
Once you have determined that your tree needs pruning, start from one side of the tree and work systematically to pluck off the excess fruit. Leave the largest, healthiest looking specimen, sometimes called the “King’s fruit”. To remove the extra fruit, care must be taken to not damage the branch spur holding the remaining fruit. Grasp the small fruit between your fingers and pull the fruit backwards so the stem snaps cleanly off at its base. You can let the plucked fruit fall to the ground beneath the tree, or save it in a bucket for the compost bin.
When you’re done, there should be just a single apple per cluster and it will look like this:
As you thin each cluster, keep your eye out for any flaws in the fruit, such as spots, bug damage or poor conformation. These are the first ones you should remove.
If you have two similar sized fruit on a cluster and can’t decide which to remove, take the one which has less sun exposure. This is usually the fruit on the underside of the leaves. You want to keep the fruit which will have the best exposure to sun and airflow.
Now that you’ve learned how to thin a fruit cluster, the final step is to determine how many clusters to keep per branch. In some cases, when a tree is producing a lot of fruit, some clusters are thinned of all fruit. As a general rule, there should be about 4” – 5” between fruit on a branch. Commercial growers often increase this span to as much as 8” – 10”. In our orchard, which is not commercial, I use my fist as a measure for minimum distance between fruit on any branch.
When you are finished, the branches will look like this:
Note the single apple per cluster and the generous spacing between ripening fruit. These remaining fruit are the best specimens of the spring fruit set, and will ripen to be of consistent size and quality which makes it easier to pick, grade and process the harvested fruit in the fall.