Thursday, January 31, 2008

maple fungus problems

This Japanese maple is wold famous. it is very popular because of it's bright red foliage. Unfortunately the variety 'Deshojo' invariably is attacked by a vicious fungus. A Japanese master said that they don't grow much older than 25 years. The fungus will get them eventually. one branch after the other will die and ruin the crown. So this happened on this tree over the past ten or so years. Every year a smaller or larger branch turned black in summer suddenly. This past summer it was very bad and I considered the tree ruined. Today I cleaned it again and cut off the dead branches. What is left is just a shadow of what the tree was once. This fungus is INCURABLE. It is in the system and no fungicide will kill the fungus. Anyway, I took a closer look at the tree an decided that it could be rescued somewhat by raising on of the smaller trees considerably and changing the front. We'll see.
In the menatime I learned that there might be a chnace to avoid this in the future: A deshojo maple should be positioned so that it is not hit by rain. Only watering by hand is OK. A positon in the greenhouse will be fine. This fungus only grows when the rain hits the crown for a few days and everything is dripping wet.

The first image is as it was two years ago. What a shame !!!


KennyC said...

wow, that was a great looking tree, I hope you are able to save what's left of it. I hope to someday expand into working with Japanese Maple, and it is good to know about the dangers of this fungus ahead of time.

Alexander Probst said...

Hello Walter!
Very interesting what you say about the care, perhaps it is successful to dam the fungus in future so.

Loren Buxton said...

Interesting this is particular to the Deshojo variety. Being particular to a red semi-dwarf and not other similar cultivars does not seem to make much sense horticulturally. I do know that it's best to keep dwarf varieties out of the rain because their growth is so tight, which decreases the ventilation between leaf nodes. I've had some fungal issues with my dwarfs, but never to the extent of losing a branch. It definitely sounds like internal bleeding, per say and not a leaf fungus.