AusBonsai

Just saw this post. Most issues have been covered. I'd just like to say that the first pics of the 'lichen' do indeed show an assortment of bark-living lichens. None of these are injurious to the trees they are growing on. Some of them shown, live inside the bark and one of them lives on the bark. They feed on nutrients that leak out naturally from some species of trees (either or both from the leaves and bark). The black dots you see are the reproductive organs of the fungal part of the lichen/alga symbiosis that makes up the lichen. They are not your problem. If your tree is dying back, it is because of something else and there is no need to scrub or carve off the lichen. You do need to find out what is really causing the problem.

Good luck. It looks like a very nice trident and you wouldn't want to lose it.
Roger

Spotted some coral rot in one of my roses

Roger wrote:Just saw this post. Most issues have been covered. I'd just like to say that the first pics of the 'lichen' do indeed show an assortment of bark-living lichens. None of these are injurious to the trees they are growing on. Some of them shown, live inside the bark and one of them lives on the bark. They feed on nutrients that leak out naturally from some species of trees (either or both from the leaves and bark). The black dots you see are the reproductive organs of the fungal part of the lichen/alga symbiosis that makes up the lichen. They are not your problem. If your tree is dying back, it is because of something else and there is no need to scrub or carve off the lichen. You do need to find out what is really causing the problem.

Good luck. It looks like a very nice trident and you wouldn't want to lose it.
Roger

I agree Roger. Just spotted this too, I have always maintained the Phantom Trident Disease as Paul has so well described it, is fungal, very likely caused by a variety of cultural (generally meaning the way people look after their trees, environmental conditions, suitability of climate etc) issues that invite problems in Japanese and Trident Maples and other deciduous trees. I'd get the tree into a free flowing relatively coarse media without disturbing the root ball too much and make very sure to allow the tree to consume the available water before watering. Under no circumstances water the foliage or allow the branches to become wet, other than by by rainfall and if it is raining a lot during the growing season as it can in Northern NSW, consider sheltering the tree as a precaution. What Paul has suggested in regards to throttling back the nitrogen makes sense as does the removal of dead growth. Winter sprays of lime sulphur work on a lot of pest and disease problems and are a simple preventative measure that I'd recommend with deciduous trees and if Joe (Jow) has said that he has sprayed trees with lime sulphur in leaf with no ill effects, that's good enough for me.

Good luck,
Mojo