Troubleshooting
Dahlia 'Senior Ball' problems — and how to fix them
Dahlia 'Senior Ball' (Dahlia 'Senior Ball') 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.
Powdery mildew
White powdery coating on leaves in late summer; improve air circulation and avoid overhead watering; treat with a potassium bicarbonate spray if severe.
Earwigs
Chew ragged holes in petals overnight; trap in rolled damp newspaper placed near stems and dispose each morning.
Aphids
Cluster on new shoot tips; dislodge with a strong water jet or treat with insecticidal soap.
Tuber rot
Caused by overwintering in damp conditions; allow tubers to dry fully after lifting and store in barely damp vermiculite or coir in a frost-free location.
Slug and snail damage
Young emerging shoots are particularly vulnerable in spring; use copper tape, biological nematode treatments, or wildlife-safe slug pellets.
Prevent dahlia 'senior ball' problems before they start
Most dahlia 'senior ball' issues are care-mismatch, not bad luck. Dial in the basics:
Dahlia 'Senior Ball' problems — FAQ
Why is my dahlia 'senior ball' powdery mildew?
White powdery coating on leaves in late summer; improve air circulation and avoid overhead watering; treat with a potassium bicarbonate spray if severe.
Why is my dahlia 'senior ball' earwigs?
Chew ragged holes in petals overnight; trap in rolled damp newspaper placed near stems and dispose each morning.
Why is my dahlia 'senior ball' aphids?
Cluster on new shoot tips; dislodge with a strong water jet or treat with insecticidal soap.
Why is my dahlia 'senior ball' tuber rot?
Caused by overwintering in damp conditions; allow tubers to dry fully after lifting and store in barely damp vermiculite or coir in a frost-free location.
Why is my dahlia 'senior ball' slug and snail damage?
Young emerging shoots are particularly vulnerable in spring; use copper tape, biological nematode treatments, or wildlife-safe slug pellets.