Beware of Phytophthora ramorum and Phytophthora kernoviaea couple of fungus-like pathogens which affect a range of trees, shrubs and other plants.

• Ramorum blight or ‘sudden oak death’ is one of the Phytophthora pathogens causing concern in UK woods and forests.
• Bark canker on oak trees and heavy leaf infestation on the understorey of rhododendrons has led to the death or removal of 4 million trees.
• Viburnums and Japanese larch are also susceptible to the disease which is in danger of spreading still further.
• Bleeding canker is a problem for 500,000 Horse Chestnut trees.The inner bark under bleeding patches is usually mottled brown-orange and dead.

These diseases, relatively new to the UK, have been brought in on stock from Asia, Europe and Western USA. The problems could be even worse than Dutch Elm disease so take care.

Action for Gardeners

• Gardeners should not compost diseased leaves particularly of  viburnum, rhododendron or oaks.
• Burning  or deep burial are the only safe disposal method.
• Report any diseased plants to Defra, the Forestry Commission or RHS
• Disinfect footwear after a walk in the forest.
• Do not replant of susceptible hosts within 12 feet for at least 3 years.

Download a fact sheet with photographs fera pdf