Rosebush fungus

Asked August 27, 2014, 11:24 PM EDT

My rosebushes have a mossy looking growth everywhere. Any idea what what it is or how to cure it?

Teton County Wyoming

1 Response

Without seeing pictures I can't say for sure, but my best guess is you are seeing mossy rose gall or spiny rose gall on your roses. The galls are caused by a wasp and if you break it open there is a larva, maybe several inside. This is not a serious problem for the roses. Pruning the roses back at the end of the growing season will remove the leaves with the galls. I attached a photo. If this is not what you are seeing, please send some photos and I will try to identify the problem. Also, here is a good bit of information on mossy and spiny rose galls.