WHEN SHOULD YOU PRUNE YOUR FRUIT TREE?
We would recommend that pruning of fruit trees is done on a mild day during the winter months; this ensures the tree is dormant. However we suggest that "stone fruit" trees, such as cherries, plums and apricots, should be pruned during the summer months whilst the trees sap is rising, as this eliminates the hightened risk of silver leaf disease.
SILVER LEAF DISEASE
Silver Leaf disease (Chondrostereum Purpureum) is a fungus whose spores penetrate a trees defences through recent wounds (such as snapped branches and pruning cuts). The spores grow fungal threads, which penetrate living wood, killing it as they proceed. The silver leaves are caused by a poison which the fungus releases that causes the outer cells on the leaf to separate- resulting in the silvery sheen from which the disease gets its name.
The silver leaves are in no way infectious themselves. Silver Leaf spores are produced in small, tiered, purple/brown structures with a white, rather woolly top that grow on dead wood on standing trees and on stumps and logs. The spores are the cause of new infection which generally break out between September and May.