|Within the past 2 days, 1/3 of my japanese maple has started to suffer from a severe wilt while the rest of the tree looks very healthy. It happened so quickly I would almost suspect that some sort of poison had gotten on some of the limbs. I've read of a fungal disease that can attack maples that seems to have similar symptoms, and the book I read says to either cut out all the affected limbs or destroy the entire tree to prevent spread. Before I decide to play tree doctor myself and destroy a fairly expensive tree, I'd like to know if there is anything else that could be causing this and if I'm running the risk of spreading the fungus to my roses and other trees by taking a wait and see approach.
|From the symptoms you describe, I'd say your maple is affected by verticillium wilt. It's a soilborne fungus that attacks and infects plant roots, grows through the vascular system, and eventually reaches all the tissues. Infected tissues die. Maples are susceptible to verticillium wilt, as are oaks, raspberries, roses, tomato plants, and many others. The fungus is persistent in the soil, so choose resistant plants rather than replanting maples in the same spot.
Before taking any drastic measures with your maple, though, why not take a section of an affected branch to your local Cooperative Extension office for a positive identification? (606) 257-5582 One of the classic symptoms of verticillium is a brownish or blackish streak in the wood. Look carefully for this sign and prune out all affected wood. Be sure to disinfect your pruners after each cut. Good luck with your maple!