Hi there - I planted a Japanese Flowering Lilac about 6 yrs ago in an area with full sun & great circulation...nothing is near it but some catmint around its base that I transplanted just last summer. I know they take a while to establish themselves however there are still so few blooms...and the tree is now about 13' tall. I noticed about 4 yrs ago the start of a light greenish/greyish mold covering its trunk about 4' up. I also noticed that there is a small canker on the base of the tree where it might have gotten nipped by our landscapers along the way. There is some dieback on mostly upper branches/twigs(very small in diameter). Any suggestions for restoring this very near & dear to my heart Lilac tree ? I really don't want to rip it out and start over again especially since it's near our patio in a highly visible spot. I would appreciate any advice!