My Santa Rosa plum has some disease that leaves a black covering on the leaves, fruit and stems, and covers everything under the t

Question

ree. There is also sap oozing from the tree. What is this and how can I treat it and save this mature plum tree? All the fruit has now dropped, so is pruning appropriate now?

Answer 1

This sounds like black sooty mold! This can be caused by many things, but most usually from aphids or other insects. As far as pruning goes- I would wait until it is cooler. Spring or Autumn will be the appropriate time to prune.

These articles will help: https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm

https://www.gardeningknowhow.com/special/organic/natural-home-pesticides-organic-garden-pest-control.htm

https://www.gardeningknowhow.com/special/organic/what-are-organic-pesticides.htm

https://www.gardeningknowhow.com/edible/fruits/plum/growing-plum-trees.htm

https://www.gardeningknowhow.com/edible/fruits/plum/plum-tree-pruning.htm