I have two HUGE white azaleas and saw this today al over their stems. Is it some kind of gall or an insect?
Looks to me like lichen...I know many bonsai folk who welcome it to their trees. It won't cause harm. This link I am attaching explains it. As well as if you wish to remove it. The process in which to accomplish that.
Here is a link that might be useful: http://www.gardeningknowhow.com/ornamental/trees/tgen/treatment-tree-lichen.htm
My suggestion would be to leave the lichen alone. It is an extremely common occurrence and not at all harmful. Often the attempts at unnecessary removal have a much more damaging impact on the plant in question.
i surely cant verify such at the distance of this photo .. we would need a closeup ...
bonsai peeps actually apply lichens to their plants ... there is absolutely no reason to remove such.. ever ....
next time.. ask before you go lopping off huge branches... unless they needed to go for other reasons ..
get us a better pic ...
I agree with Ken...a close up of the stuff attached to the branches, just to verify for certain that is what is going on. I've never known anyone to remove lichen personally though.
Think of it as two plants for one. I get lichen on my yellow Northern Lights azalea. It's persistent and doesn't disappear from year to year and it does no damage (beyond causing one to lop off perfectly healthy branches). And that sure looks like lichen to me.
"A lichen is a composite organism consisting of a fungus (the mycobiont) and a photosynthetic partner (the photobiont or phycobiont) growing together in a symbiotic relationship." (Wiki)
Thanks for info. This stuff is kind of sticky. And all over
If it's sticky it could be woolly aphid. Try to rub some off with a finger. Aphids would rub off easily, lichen would resist.
I think you may have hit the nail on the head so to speak. This would be different than scale correct? I looked it up and it does very much look the same many thanks...now for what to do!
There is also a variety of scale that looks very similar.....cottony scale. And there are a couple varieties of this that attacks azaleas specifically, azalea bark scale and cottony azalea scale. Scale is not the easiest of insect problems to control but I would start with horticultural oil.
Glad you provided the close up :-)) From the distance of the first photo it really does look like lichen.....which is far more common in my area than the scale.