Why does my plum tree drop the fruit? It blooms very well then forms the fruit, but then drops 90 percent of them.

Question

It is a red plum, not sure of the type. It is in a spot that gets very wet in the spring. I didn’t intentionally plant it there. I threw out the seed after eating a plum and it grew. The soil is peat with 8″ of dirt on top.

Answer 1

I would imagine a soil sample would reveal highly acidic soil, as peat will bring the pH way down. This will make phosphorus and potassium unavailable to the tree, which will prevent proper fruit formation.

I would recommend adding dolomitic lime, and a good amount of compost to the area. This will help balance out the pH, along with give the plant a little help in replenishing nutrients. By next year, you should see better crop production.