My yoshino tree is dying! All the leaves on the bottom are brown and now the top are starting to be brown. I bought it about 13 months ago. It's relatively young.
Certified GKH Gardening Expert
This article has some common diseases that affect this plant at the bottom of the page. They may be helpful as well: https://edis.ifas.ufl.edu/st524
However, I am afraid it is highly possible that the tree may be affected by Verticillium wilt. This article has more information: