Q: I have cedar-apple rust on an apple tree not far from a cedar tree. If I move the apple to the other side of the yard will it help prevent the disease?

A: Cedar-apple rust is a major problem for commercial apple growers. They send crews through the woods near their orchards to destroy the cedar trees that are alternate hosts for this defoliating disease. Since the rust spores can affect apples within a half-mile of the infected cedar tree, moving your apple tree won’t help.

Spraying with myclobutanil (Immunox) at labeled intervals will partially control the disease. You can help break the disease life cycle by raking and removing all apple leaves after they fall in winter and by examining all cedar trees in your neighborhood for the walnut-sized disease galls, which should be destroyed.

Cedar-Apple Rust pictures

cedar apple rust gall on cedar