Old, established azalea plants getting heavy moss covering all of the branches. Is this a disease? I live in the Seattle, WA. area.
Moss on Azalea Plant
Certified GKH Gardening Expert
It is most likely lichen. It is not harmful to the plant, but if you want to get rid of it, this article will help:
If lichen is not the issue and it's indeed moss, this article will help: https://www.gardeningknowhow.com/plant-problems/weeds/moss-on-plants.htm