our natural growing Arbutus has brownish/black leaves again this year. Other years I cut off the brown leaves, but the tree is getting too big to continue that method. It is located beside a fir tree surrounded by heathers and rhodos, which all seem to be doing well. The tree does get watered in the summer time. Should watering be avoided, and/or what else might we do?
Just adding what I mentioned in a private conversation with Evelyn: Locally-grown arbutus are attacked by a suite of diseases / pathogens, such that pinpointing a specific issue is difficult. Personally, I would leave it unwatered during the summertime to better mimic the prevailing local conditions--too much water and you may be boosting the pathogens (most of which are fungal / bacterial) relative to any gains to the plant itself.
