Troubleshooting
Yarrow 'Moonshine' problems — and how to fix them
Yarrow 'Moonshine' (Achillea 'Moonshine') 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.
Flopping stems
Rich soil, shade, or overwatering make stems lax; grow lean and sunny, and cut back after the first flush to encourage sturdier rebloom.
Powdery mildew
Gray-white film forms in humid, crowded spots; improve spacing and airflow and avoid wetting foliage.
Root rot
Wet, heavy soil rots the crown, especially in winter; ensure sharp drainage and avoid soggy sites.
Center die-out
Clumps open up and weaken at the middle after a few years; divide every two to three years in spring to rejuvenate.
Prevent yarrow 'moonshine' problems before they start
Most yarrow 'moonshine' issues are care-mismatch, not bad luck. Dial in the basics:
Looking for yarrow 'moonshine' in general rather than its problems? Read the full yarrow 'moonshine' care guide — light, water, soil and feeding.
Yarrow 'Moonshine' problems — FAQ
Why is my yarrow 'moonshine' flopping stems?
Rich soil, shade, or overwatering make stems lax; grow lean and sunny, and cut back after the first flush to encourage sturdier rebloom.
Why is my yarrow 'moonshine' powdery mildew?
Gray-white film forms in humid, crowded spots; improve spacing and airflow and avoid wetting foliage.
Why is my yarrow 'moonshine' root rot?
Wet, heavy soil rots the crown, especially in winter; ensure sharp drainage and avoid soggy sites.
Why is my yarrow 'moonshine' center die-out?
Clumps open up and weaken at the middle after a few years; divide every two to three years in spring to rejuvenate.