Troubleshooting
Ashy Broom problems — and how to fix them
Ashy Broom (Genista cinerea) is generally low-drama, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Die-back after hard pruning
Brooms produce new growth only from green wood — cutting back into old, bare stems almost always causes branch death or kills the plant entirely. Trim lightly immediately after flowering, removing only the flowered tips.
Gall mite (Aceria genistae)
Tiny eriophyid mites cause distorted, witches'-broom-like proliferation of buds and shoots, particularly in warm summers. Remove and destroy affected shoots promptly; no chemical control is registered or reliably effective.
Prevent ashy broom problems before they start
Most ashy broom issues are care-mismatch, not bad luck. Dial in the basics:
Ashy Broom problems — FAQ
Why is my ashy broom die-back after hard pruning?
Brooms produce new growth only from green wood — cutting back into old, bare stems almost always causes branch death or kills the plant entirely. Trim lightly immediately after flowering, removing only the flowered tips.
Why is my ashy broom gall mite (aceria genistae)?
Tiny eriophyid mites cause distorted, witches'-broom-like proliferation of buds and shoots, particularly in warm summers. Remove and destroy affected shoots promptly; no chemical control is registered or reliably effective.