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Cedar-Apple Rust on Junipers: Identification and Management

The orange, gelatinous "cocoons" with worm-like projections on your junipers are cedar-apple rust galls (Gymnosporangium juniperi-virginianae). They appear in wet spring weather. The fungus requires both juniper/cedar and apple/crabapple to complete its life cycle.

On junipers, it's mostly cosmetic—twig dieback only if severe. Prune galls by April 1. No treatment needed unless you grow apples nearby, where it causes serious leaf spots and fruit damage. Resistant apple cultivars are the best solution.

Trees: Sooty Mold on Citrus: Controlling the Underlying Insect Infestation Safely; Sapsucker Damage on Young Oak: Same Culprit, Different Tree; Pine Tree Yellowing Needles and White Sudsy Substance: Insect Identification; Orange Powder on Pine Trunk: Fusiform Rust, Not Lawnmower Damage; Pine Cone Absence in Massachusetts: Not Necessarily a Problem; Identifying a Tree with Round Cones & Tiny Needles: Bald Cypress; Pine with Black Sooty Mold on Needles: Scale Insect Infestation; Cedar-Apple Rust on Apple and Peach Trees; Perfectly Round Holes in Pine Trees: Sapsucker Damage, Not Carpenter Bees; Identifying a Pine Tree from a Photo

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