Question: My plum is dropping most of its fruit. They’re not any bigger than marbles. What can I do to stop it?
Answer: Several things can cause fruit drop. Wind will blow them out of the trees, and hail can knock them loose. If you’ve had a late frost, that can kill the embryos, resulting in aborted fruit a few days later. Insect damage can cause them to fall as well. A certain amount of drop isn’t all that bad, since the fruit need to be thinned anyway. Hopefully it won’t be excessive. By the time you see it, there isn’t much you can do to stop it.