Q&A Diseases: Brown rot

Last year my apples and plums went brown and rotten before they were really ripe. How can I prevent this from happening again?

Mary Payne: The problem is caused by a fungus we call brown rot, which can affect virtually any fruit, and last year seemed to have been a particularly bad one for it. Eventually creamy coloured pustules that release the spores appear in rings on the fruits. The spores of the fungus usually enter the fruits through damage caused by birds, wasps or cracks.

You need to gather up all the affected fruits and bin them. Do not compost them, or you will simply return the spores to the garden. You will find that some of the fruits hang on the tree right through the winter months and become mummified. It is essential to remove these fruits, as they provide a source for re-infection next season.