That’s unfortunate. It’s unlikelly to be too much or too little fertilizer. Premature fruit drop is common among fruit trees; it’s Mother Nature’s way of reducing the load—especially if you do not thin the fruit load yourself (prune when plums are about 3/4-inch long, leaving 4 to 6 inches between remaining fruits). Weather could be a factor; high heat in early spring can stress the tree, and if conditions in general have been dry, the tree may not be well irrigated.
That’s unfortunate. It’s unlikelly to be too much or too little fertilizer. Premature fruit drop is common among fruit trees; it’s Mother Nature’s way of reducing the load—especially if you do not thin the fruit load yourself (prune when plums are about 3/4-inch long, leaving 4 to 6 inches between remaining fruits). Weather could be a factor; high heat in early spring can stress the tree, and if conditions in general have been dry, the tree may not be well irrigated.