Troubleshooting
Rowan problems — and how to fix them
Rowan (Sorbus aucuparia) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Fireblight
Bacterial disease blackening and wilting shoots and blossom into a 'shepherd's crook'. Prune out affected wood well below the damage, disinfecting tools between cuts.
Rowan sawfly
Larvae can rapidly strip the pinnate leaves in early summer. Light infestations are tolerable; pick off larvae or accept some defoliation on established trees.
Apple scab and rust
Fungal spotting of leaves and fruit in wet seasons. Rake up and bin fallen leaves to reduce overwintering spores; usually cosmetic on a healthy tree.
Eating raw berries
Raw fruit is mouth-puckering and causes stomach upset from parasorbic acid. Always cook, or freeze first, before using in jelly or preserves.
Prevent rowan problems before they start
Most rowan issues are care-mismatch, not bad luck. Dial in the basics:
Looking for rowan in general rather than its problems? Read the full rowan care guide — light, water, soil and feeding.
Rowan problems — FAQ
Why is my rowan fireblight?
Bacterial disease blackening and wilting shoots and blossom into a 'shepherd's crook'. Prune out affected wood well below the damage, disinfecting tools between cuts.
Why is my rowan rowan sawfly?
Larvae can rapidly strip the pinnate leaves in early summer. Light infestations are tolerable; pick off larvae or accept some defoliation on established trees.
Why is my rowan apple scab and rust?
Fungal spotting of leaves and fruit in wet seasons. Rake up and bin fallen leaves to reduce overwintering spores; usually cosmetic on a healthy tree.
Why is my rowan eating raw berries?
Raw fruit is mouth-puckering and causes stomach upset from parasorbic acid. Always cook, or freeze first, before using in jelly or preserves.