I have a lemon tree that dried up about 60%. One thing that we found was some huge brown fungus at the trunk. We cut all the dry parts off the tree and left the parts that look alive. Also, the tree grew real big and we decided to cut some of the branches, and after that we observed the tree start to dry up. Some of the leaves started to have black spots. What happened and is there is anything we can do? We love the tree and for many years it gave us plenty of lemons.
Brown Fungus Lemon Tree
Certified GKH Gardening Expert
The mushroom type growth is probably not what is hurting the plant. They tend to be opportunistic and will attach to trees that are unwell to begin with. There are a few things that could be wrong with your tree. The first is simple old age. Trees have lifespans like animals do and citrus trees tend to live 20 years or so. If your tree is this old or older, it may just be dying from old age and not much can be done for it.
Another possibility is that it has a fungus (not the mushroom kind). The tree should be treated with a fungicide to get rid of the harmful fungicide.