I Love this thread...even tho I don’t comment...we moved to a harsher gardening property and are in the midst of remodel. We now have @2 acres to deal with. Planning a “courtyard garden” to be able to grow some veggies in future (protect from varmints and have decent soil in raised beds). Oh. And I love holly trees...several on the property, altho they seem to be struggling.
I'd recommend looking up how to prune the Holly trees, (or call in a Professional) and this coming spring, when you see growth on the Holly or other things around it, give it a fertilization with Miracid, which is from Miracle Grow, and has the acidity that Holly likes.