Troubleshooting
Greek yarrow problems — and how to fix them
Greek yarrow (Achillea taygetea) 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
Can occur in humid summers or where air circulation is limited. Ensure plants are well spaced, water at the base only, and remove affected foliage promptly. Preventative sulphur-based sprays help in mildew-prone gardens.
Winter crown rot
Wet winter conditions in poorly drained soils are fatal. Improve drainage with grit or plant on a raised berm. In wet climates, a light gravel mulch around the crown helps deflect moisture.
Clump decline
Like most yarrows, plants become woody and die out at the centre after 3–5 years. Regular division in spring (every 3 years) and replanting of young outer sections keeps plants vigorous.
Prevent greek yarrow problems before they start
Most greek yarrow issues are care-mismatch, not bad luck. Dial in the basics:
Looking for greek yarrow in general rather than its problems? Read the full greek yarrow care guide — light, water, soil and feeding.
Greek yarrow problems — FAQ
Why is my greek yarrow powdery mildew?
Can occur in humid summers or where air circulation is limited. Ensure plants are well spaced, water at the base only, and remove affected foliage promptly. Preventative sulphur-based sprays help in mildew-prone gardens.
Why is my greek yarrow winter crown rot?
Wet winter conditions in poorly drained soils are fatal. Improve drainage with grit or plant on a raised berm. In wet climates, a light gravel mulch around the crown helps deflect moisture.
Why is my greek yarrow clump decline?
Like most yarrows, plants become woody and die out at the centre after 3–5 years. Regular division in spring (every 3 years) and replanting of young outer sections keeps plants vigorous.