Avoiding silver leaf disease

Pruning now can help reduce a common fungal problem

SOME trees need a summer trim to help protect them from a fungal disease. These varieties include plums and gages, edible and ornamental cherry varieties, apricots, peaches, nectarines, rhododendrons and laburnum.

They are cut back now, rather than when they are dormant like other deciduous fruiting trees such as apples and pears, because they are vulnerable to a common fungal problem called silver leaf disease.

This is caused by a fungus called Chondrostereum purpureum, the spores of which are most prevalent between September and May.

Because it is easily transmitted via wounds such as those caused by pruning, susceptible trees and shrubs are pruned when the risk is at its lowest.

Symptoms of silver leaf include the leaves developing a silvery sheen, dark stains when branches are cut open and, on dead branches, bracket fungi with a pale, woolly upper surface and a purple-brown undercarriage.

The main way of controlling the disease is to prune in summer when spores are less of a problem and wounds dry faster.