Troubleshooting
Common hollyhock problems — and how to fix them
Common hollyhock (Alcea rosea) 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.
Hollyhock rust (Puccinia malvacearum)
The most serious and ubiquitous hollyhock problem — orange-yellow pustules on leaf undersides, leading to premature defoliation. Remove and bin (not compost) infected leaves promptly; grow new plants from seed each year and avoid overwintering infected rosettes.
Aphid infestations
Large colonies of black bean aphids or green peach aphids cluster on soft new growth and flower buds in late spring. Blast off with water, encourage ladybirds and lacewings, or apply insecticidal soap. Ant-tended colonies are harder to manage.
Slug and snail damage
Young rosettes and spring shoots are highly susceptible to slug damage, which shows as ragged holes and silvery slime trails. Apply iron phosphate pellets around plants or use copper barriers; inspect plants after rain.
Prevent common hollyhock problems before they start
Most common hollyhock issues are care-mismatch, not bad luck. Dial in the basics:
Looking for common hollyhock in general rather than its problems? Read the full common hollyhock care guide — light, water, soil and feeding.
Common hollyhock problems — FAQ
Why is my common hollyhock hollyhock rust (puccinia malvacearum)?
The most serious and ubiquitous hollyhock problem — orange-yellow pustules on leaf undersides, leading to premature defoliation. Remove and bin (not compost) infected leaves promptly; grow new plants from seed each year and avoid overwintering infected rosettes.
Why is my common hollyhock aphid infestations?
Large colonies of black bean aphids or green peach aphids cluster on soft new growth and flower buds in late spring. Blast off with water, encourage ladybirds and lacewings, or apply insecticidal soap. Ant-tended colonies are harder to manage.
Why is my common hollyhock slug and snail damage?
Young rosettes and spring shoots are highly susceptible to slug damage, which shows as ragged holes and silvery slime trails. Apply iron phosphate pellets around plants or use copper barriers; inspect plants after rain.