Troubleshooting
Coreopsis 'Ruby Sunset' problems — and how to fix them
Coreopsis 'Ruby Sunset' (Coreopsis 'Ruby Sunset') 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.
Crown rot
The most common issue; caused by wet or waterlogged soil, especially in winter. Ensure excellent drainage and avoid mulching directly against the crown.
Powdery mildew
Can appear in humid, stagnant-air conditions in late summer. Improve air circulation; resistant varieties are available.
Aster yellows
Phytoplasma disease spread by leafhoppers, causing distortion and yellowing. Remove and destroy affected plants; control leafhoppers.
Short-lived performance
Hybrid Coreopsis can decline after 2-3 years. Divide every other year in spring to rejuvenate, or treat as a short-lived perennial.
Aphids and mealybugs
Occasional pests on tender growth. Treat with insecticidal soap or neem oil at first sign of infestation.
Prevent coreopsis 'ruby sunset' problems before they start
Most coreopsis 'ruby sunset' issues are care-mismatch, not bad luck. Dial in the basics:
Coreopsis 'Ruby Sunset' problems — FAQ
Why is my coreopsis 'ruby sunset' crown rot?
The most common issue; caused by wet or waterlogged soil, especially in winter. Ensure excellent drainage and avoid mulching directly against the crown.
Why is my coreopsis 'ruby sunset' powdery mildew?
Can appear in humid, stagnant-air conditions in late summer. Improve air circulation; resistant varieties are available.
Why is my coreopsis 'ruby sunset' aster yellows?
Phytoplasma disease spread by leafhoppers, causing distortion and yellowing. Remove and destroy affected plants; control leafhoppers.
Why is my coreopsis 'ruby sunset' short-lived performance?
Hybrid Coreopsis can decline after 2-3 years. Divide every other year in spring to rejuvenate, or treat as a short-lived perennial.
Why is my coreopsis 'ruby sunset' aphids and mealybugs?
Occasional pests on tender growth. Treat with insecticidal soap or neem oil at first sign of infestation.