Cedar-Apple Rust

Yesterday, after a steady morning rain, my wife called me outside to look at strange, gelatinous growths in our eastern red cedar trees.  Bright orange, tennis ball sized and characterized by numerous tendrils, these alien ornaments had not been observed in previous years.

Cedar-apple rust is a unique fungus that utilizes both eastern red cedars and a tree from the rose family (primarily apples) to complete its life cycle.  Spores infect the red cedars in summer, forming small galls by the following spring.  Often called "cedar apples," the galls enlarge over the next year and spawn the gelatinous tendrils after spring rains; these odd structures release spores that, spread by the wind, infect nearby apple trees.  Spores released by lesions on the apple leaves then reinfect the cedars during the summer months, completing the cycle.

In retrospect, we recently lost a diseased crabapple tree that had grown near the red cedars.  In addition, our hawthorne tree has been losing limbs over the past year and now has yellow spots on some of its leaves; hawthornes, like apple trees, are members of the rose family and are susceptible to cedar-apple rust.  Not inclined to use fungicides, we'll trim out the dead wood as necessary and hope for the best (though the hawthorne's fate seems clear).