I have had a fruit plum tree for 6 years in a pot. It has not produced any fruit as yet, but last 2 years the possible fruit fell as result of the stalks changing yellow and falling of tree before fruiting. Can you advise, please?
Stone fruits, such as Plums do not make great container trees.
The roots are quite vigorous and quickly outgrow the containers.
It is difficult to provide the room and the growing conditions that the tree needs to produce fruit.
Citrus Trees and Blueberries are excellent container fruit trees.
Perhaps you could plant out the Plum Tree into the garden and give it some room to grown.
Here are some articles with more information.