What is the white frothy substance on my Pittisporum?
By Tamar
United Kingdom 
I have a large, well-established and otherwise healthy pittisporum tree. I've noticed over the summer that there is a white frothy substance coming out of one place on the bark. It has quite a strong smell, a bit like a solvent, and seems to have been very attractive to wasps and flies. There is also a small amount of resin coming from the bark in several other places.
5 Oct, 2009
Answers
sounds like a bacterial canker. dont know if it can be treated. hope so.
5 Oct, 2009
Pittosporumare are prone to pests and diseases I know that leaf spot from warm wet weather and root rot diseases can be problems for this plant and I was told not to plant in areas where water accumulates so I planted mine on a slope. You could look up gall, dieback and stem blight for this plant. Not much help I'm afraid.
5 Oct, 2009
As Fractal says, sounds like a bacterial infection of some kind, not sure what. If its possible, you should cut out affected stems as far back as possible, though if its on the main trunk, that won't be possible. this kind of infection can be caused by injury to the bark, or from bad pruning, or anything else that damages the bark, though it doesn't happen that often.If the main stem is affected, if its possible, I'd cut it back past the point where the infection is present, no matter how low that is - the plant will probably succumb to the infection anyway if you don't cut out infected parts.
5 Oct, 2009
This sounds rather like the 'unidentified' disease that killed my cherry tree a few years back. The fluffy white stuff sounds to me like either woolly aphids or the woolly species of scale insect, but I'm not aware that these smell at all. Have you had a dig around in the ooze to see if there is anything living under it?
6 Oct, 2009
Not sure about this but it doesn't sound very good? Could be a bacterial infection. Not even sure a picture would help here though it could be interesting to see.
5 Oct, 2009