Concerns my plum, damson and greengage trees

Question

On an extremely windy and rainsoaked day all my plum trees lost most of their leaves and flowers. All trees have new leaves growing and some fruits but the fruits are tiny and misshapen and very dark in colour. Could this be pocket plum or something else and how should I treat it? Apple and pear trees have not suffered in the same way.

Answer 1

I don't think it is plum pocket. Normally, with that disease, the fruit have a pockmarked look to them.

It sounds like the plums were affected by a stone fruit exclusive fungus (which is why the apple and pear are fine). It was probably attacking the trees before the storm came, but the weakened leaves and fruit could not handle the high winds.

The fruit you are seeing now is a last ditch effort on the tree's part to produce seeds this year. They will not produce any kind of quality fruit, so it is best to remove the fruit now to prevent the tree from focusing energy on them. This will also help to redirect the energy to the leaves, which will help the trees recover faster for next year.

Treat the trees with a fungicide once this year and then get them on a schedule for treatment for next year. This article is for peaches and nectarines, but the same spray schedule applies to plums:
http://ag.udel.edu/extension/horticulture/pdf/hg/hg-22.pdf