Japenese Maple – Nectria cinnabarina canker
We think our tree has Nectria cinnabarina canker, and we just wondered how we can stop this spreading? It is on one branch badly, and has just started on a small area of another. Please help, as we love our tree!
Certified GKH Gardening Expert
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It is normally not fatal, but can weaken the tree so that it is susceptible to other diseases and pests. Treat the tree with a fungicide and keep a close eye on it for other problems.