Horse Chestnut Bleeding Canker (Pseudomonas syringae pv. aesculi)
Horse chestnut bleeding canker (HCBC) is a relatively new disease in the UK although it has had a devastating impact. It has killed around a third of horse chestnut trees since it was introduced from North West Europe in the early 2000s. Many of the surviving trees still show signs of mild to moderate infection. HCBC is caused by the bacterium Pseudomonas syringae pv. aesculi. The bacterium enters the tree bark via natural openings or wounds. As the infection progresses weeping lesions develop which ooze a reddish brown or black gummy liquid. This is where the name ‘bleeding canker’ comes from. If the lesions enlarge to encircle the whole trunk the tree will eventually die. There is no control available, but some trees seem to be more resistant.
Find out more about horse chestnut bleeding canker via these resources
- Research note on how the disease develops and spreads from the Forestry Commission