What is Cedar-Apple Rust?
Cedar-apple rust is the name of a group of closely related diseases caused by fungi that infects both junipers and woody rosaceous plants such as apple, crabapple, hawthorn and quince.
What does cedar-apple rust look like?
Symptoms appear in late May as circular, yellow-orange areas on leaves. The under-surfaces of these diseased areas often have a fringed appearance.
How do I save a tree or shrub infected with cedar-apple rust?
You can control cedar-apple rust using chlorothalonil. Apply treatments when flower buds first show color, when half of the flowers are open, at petal-fall. We recommend three treatments to get control. Fertilizing also helps the tree fight the fungus.