Cedar Apple Rust activity

Asked May 9, 2017, 6:26 PM EDT

Can you tell me if the Cedar Apple Rust spores are finished being let loose by the galls on the cedar trees for this spring in Frederick Md? I see only dark brown galls presently on the nearby cedar trees. I never noticed the orange tendrils. Thank You

Frederick County Maryland

1 Response

The galls on cedar trees sporulate about the same time that crabapple trees bloom.

We can't say exactly when particular crabapple trees bloomed in Frederick, but that's what you want to watch for. Chances are that bloom is finished for this year, but every year is a bit different depending on weather.

Here is info about cedar apple rust from our website: http://extension.umd.edu/hgic/rust-diseases-trees-and-shrubs

If you are growing apples, look in the Fruit section of Grow It Eat It on our website. See: Tree Fruit> Apple> Diseases> Rust. At the bottom of the screen you can link to a spray schedule.