We have a plum tree that is reasonably healthy. It flowers in the spring and forms fruit, but about this time of the year the still green fruit falls down. We now have only a few plums on the tree and the ground covered with them. It looks like they all have a small hole on the side. What could be the problem and how to fix it? Thank you
Plum Tree Problem
Certified GKH Gardening Expert
Premature fruit drop is normally the result of poor pollination or an insect problem. Peach tree borers can also affect plums. This article will help determine if this is a problem: https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-borer.htm
Overbearing is another possibility. When the fruit is pea size, begin thinning to prevent fruit drop. This will reduce the energy of the tree so it can put more into the production of fruit. If pollination/fertilization is at too great a level for the tree to sustain, all of the set fruit will simply drop. You can also thin the blossoms rather than the fruit.