Help -- rose leaves turning yellow
My mother has some knockout roses and a couple of other very old roses (no idea what they are --- they were rooted last year ---- luckily ---- from my grandfather's and grandmother's OLD rose --- lucky because it finally gave up the ghost).
In the last few days some of the leaves have begun to turn yellow. All the roses are still blooming.
We put some bloombuster liquid fertilizer on them Sunday -- don't know if that may have caused the problem.
Any ideas?? Solutions??