Troubleshooting
Dahlia 'Bishop of Llandaff' problems — and how to fix them
Dahlia 'Bishop of Llandaff' (Dahlia 'Bishop of Llandaff') 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.
Aphids
Particularly prevalent on young growth; use insecticidal soap or encourage natural predators like ladybirds.
Powdery mildew
Can affect leaves in late season; improve air circulation and treat with a dilute bicarbonate or sulphur-based fungicide.
Earwigs
Petals are nibbled overnight; use pheromone traps or dry straw-filled plant pots as traps near the plants.
Tuber rot in storage
Lift after first frost, dry tubers for a week, and store in slightly damp compost or peat in a frost-free shed.
Virus mosaic
Distorted mottled leaves indicate virus spread by aphids; remove and destroy affected plants, do not compost.
Prevent dahlia 'bishop of llandaff' problems before they start
Most dahlia 'bishop of llandaff' issues are care-mismatch, not bad luck. Dial in the basics:
Dahlia 'Bishop of Llandaff' problems — FAQ
Why is my dahlia 'bishop of llandaff' aphids?
Particularly prevalent on young growth; use insecticidal soap or encourage natural predators like ladybirds.
Why is my dahlia 'bishop of llandaff' powdery mildew?
Can affect leaves in late season; improve air circulation and treat with a dilute bicarbonate or sulphur-based fungicide.
Why is my dahlia 'bishop of llandaff' earwigs?
Petals are nibbled overnight; use pheromone traps or dry straw-filled plant pots as traps near the plants.
Why is my dahlia 'bishop of llandaff' tuber rot in storage?
Lift after first frost, dry tubers for a week, and store in slightly damp compost or peat in a frost-free shed.
Why is my dahlia 'bishop of llandaff' virus mosaic?
Distorted mottled leaves indicate virus spread by aphids; remove and destroy affected plants, do not compost.