Troubleshooting
Koehne's rowan problems — and how to fix them
Koehne's rowan (Sorbus koehneana) 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.
Fire blight
Wilting, blackened shoot tips indicate Erwinia infection. Remove all infected wood well below visible damage with sterilised secateurs; preventive copper spray at bud-break is recommended.
Scarcity in nursery trade
Not widely available. Source from specialist tree nurseries. Plants sold may be grafted; confirm the rootstock to anticipate suckers from the base.
Rowan aphids
Clusters of rowan leaf-curling aphids (Dysaphis sorbi) distort young foliage in spring. Blast off colonies with water; apply insecticidal soap or neem oil for persistent infestations.
Prevent koehne's rowan problems before they start
Most koehne's rowan issues are care-mismatch, not bad luck. Dial in the basics:
Koehne's rowan problems — FAQ
Why is my koehne's rowan fire blight?
Wilting, blackened shoot tips indicate Erwinia infection. Remove all infected wood well below visible damage with sterilised secateurs; preventive copper spray at bud-break is recommended.
Why is my koehne's rowan scarcity in nursery trade?
Not widely available. Source from specialist tree nurseries. Plants sold may be grafted; confirm the rootstock to anticipate suckers from the base.
Why is my koehne's rowan rowan aphids?
Clusters of rowan leaf-curling aphids (Dysaphis sorbi) distort young foliage in spring. Blast off colonies with water; apply insecticidal soap or neem oil for persistent infestations.