Pruning fruit trees encourages a good size and shape, keeps the tree productive and helps remove dead and damaged wood. Many fruit trees, such as apples and pears, are pruned in winter, but plum trees can be susceptible to silver leaf disease if pruned at this time. Plum trees are therefore best pruned in spring or summer.
Silver leaf disease is a debilitating fungal disease that affects the whole of the Prunus family, including plums, apricots, cherries, and Portuguese laurel. The fungus enters the plant through wounds, turning the leaves silver. Eventually the whole branch dies back. Pruning plum trees in spring or summer enables the tree’s pruning wounds to heal before the spores of silver leaf disease become active during the damp months of autumn and winter.