My kumquat tree is an old established tree that is suddenly losing leaves, has leaves turning yellow, and has a scaly growth on the bark. I've attached a picture of the bark issue. Any ideas as to what might be wrong and how to treat it. Don't want to lose this treasured tree!!! Thanks.
Looks as though your tree has a crop of lichen, 2 different kinds visible in photo. In itself, lichen is not harmful. Dunno what might be causing your kumquat's leaf drop. What's your rainfall been like? (Here, we are roasting along with the plants.) Not enough? Too much? Temps like a slow oven?
