Rust on lilac bush?
I have a couple of new lilac bushes my boss recently bought from a wholesale nursery (i.e. cheap, no guarantee) and gave me to have planted around the property. We've had them about a month, one is dead, and the other has quarter size orange spots on the leaves?
I know nothing about lilacs, other than I like the smell. Do they get "rust"? They are planted on a slope, in sandy loam soil, so excellent drainage, and we have single digit humidity. They are watered by the sprinkler system, 3 times a week, early morning, (5-6am), so there shouldn't be water sitting on the leaves for long. The sprinkler does go high enough it gets water on the leaves. On really hot days, if it droops, I suppliment the water by a hose on the ground.
Suggestions? What am I doing wrong and how do I fix it?