Fruit Tree Thinning Workshop
By Jutta Thoerner Master Gardener
I had a lot of small fruit last year and much of the fruit dropped prematurely. How can I prevent this from happening again? Robert, San Miguel
This premature fruit drop is referred to as “June drop”, which occurs in our area around May. It is a natural process that thins fruit in an attempt to prevent overbearing – or a crop load that the tree cannot successfully support.
However, this natural thinning is sometimes not enough. Signs that too much fruit is produced by the tree include broken branches laden with fruit, small fruit or alternate bearing of crop. In this extreme drought year, thinning your fruit is particularly important. Manually thinning will help your tree to get through this season less stressed, minimizing susceptibility to diseases and even sunburn. Some examples of trees that benefit from thinning include apples, Asian pears and certain European pears. These trees produce flower clusters from each bud and each flower can become a fruit. Thin these pome fruits to one or two fruit per cluster and at least 6-8 inches apart. The size of the fruit should be 0.5 inches to 1 inch in size at the time of thinning.
Stone fruits such as apricots, plums, peaches and pluots produce one fruit per bud and often, for example with apricots, on the entire length of the branch. Thin all the fruit clusters to just one fruit and leave 2-4 inches between each fruit. Thin when the fruit is ¾ to 1 inch in diameter.
If you have small trees or believe in keeping your trees small with summer pruning, hand thinning is the easiest and also produces the most accurate results. If you have a large tree and ladder climbing is no longer your hobby, attach a short rubber hose or cloth to a long pole. Strike individual fruit or clusters once or twice to break the fruit up and it will drop. Remember to clean the dropped fruit off the ground to lessen the spread of diseases. If you want to see a demonstration on “How to thin fruit”, join the Master Gardeners on April 23rd @ 1 30 pm for a one hour workshop in the Demonstration Garden (Garden Of The Seven Sisters).