Troubleshooting
Fringed Coreopsis problems — and how to fix them
Fringed Coreopsis (Coreopsis integrifolia) 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 foliage occurs in humid, low-airflow conditions. Improve spacing and avoid overhead watering. Affected foliage is mainly cosmetic; the plant typically recovers as conditions dry out.
Aphids
Soft-bodied green or black aphids cluster on young shoot tips and flower buds in spring. A strong jet of water or insecticidal soap spray is usually sufficient. Encourage natural predators such as ladybirds and lacewings.
Crown rot in poorly drained soil
Crowns rot at the base when soil remains waterlogged over winter. Always plant in well-draining positions; raise beds or add grit if drainage is suspect. Dividing crowns every 3–4 years also improves plant vigour.
Prevent fringed coreopsis problems before they start
Most fringed coreopsis issues are care-mismatch, not bad luck. Dial in the basics:
Looking for fringed coreopsis in general rather than its problems? Read the full fringed coreopsis care guide — light, water, soil and feeding.
Fringed Coreopsis problems — FAQ
Why is my fringed coreopsis powdery mildew?
White powdery coating on foliage occurs in humid, low-airflow conditions. Improve spacing and avoid overhead watering. Affected foliage is mainly cosmetic; the plant typically recovers as conditions dry out.
Why is my fringed coreopsis aphids?
Soft-bodied green or black aphids cluster on young shoot tips and flower buds in spring. A strong jet of water or insecticidal soap spray is usually sufficient. Encourage natural predators such as ladybirds and lacewings.
Why is my fringed coreopsis crown rot in poorly drained soil?
Crowns rot at the base when soil remains waterlogged over winter. Always plant in well-draining positions; raise beds or add grit if drainage is suspect. Dividing crowns every 3–4 years also improves plant vigour.