Achillea ptarmica
This species forms clumps that slowly spread by short rhizomes. Plants carry loose clusters of small white daisies through much of summer. It stands out because it tolerates slightly moister soil than many yarrows. Stems are shorter than the tall border types and fit mid‑border positions. Double forms in The Pearl Group are common in gardens and for cutting. Provide sun to light shade and average, well‑drained soil for best results.
At‑a‑glance
- Group/Class: Species; herbaceous perennial
- Height × spread: 18 to 24 in (45 to 60 cm) × 18 to 24 in (45 to 60 cm)
- Bloom window: June to September
- Color & flower form: White daisies; some forms have double, pompon‑like heads
- Fragrance: 1 trace
- USDA hardiness: zones 3 to 9
- Breeder / Year / Origin: unknown, unknown, Europe and western Asia
- Cut‑flower notes: Used fresh or dried; NC State trials of ‘Pearl Reselected’ reported a short vase life around 3 days; harvest fully open for best results.
- Pet safety: unknown
How it differs
- Prefers slightly more moisture than typical meadow yarrow
- White blooms and many double forms rather than flat plates
- Lower stature suits mid‑border and small gardens
- Tends to spread slowly by rhizomes
Strengths
- Long summer bloom in sun
- Good for fresh and dried arrangements
- Tolerates light shade
- Deer resistant
Care in one minute
- Site: full sun to light shade.
- Soil: average, well‑drained; tolerates slightly moister sites than many yarrows.
- Water: regular moisture the first season, then moderate.
- Feeding: light; excessive fertility encourages lax growth.
- Grooming: deadhead to prolong bloom; divide clumps every 2 to 3 years.
- Winter: hardy in the stated zones without special protection.
Watch‑outs
- Can sprawl or appear weedy if not divided
- Avoid heavy, wet soils
- May need division every few years to maintain vigor
Best uses (tags)
borders; cutting; cottage‑garden; pollinators
Provenance note
Native to Europe and western Asia; double selections grouped as The Pearl Group are widely grown for cut flowers.
References
- Missouri Botanical Garden – Plant Finder: Achillea ptarmica (The Pearl Group)
- RHS – Achillea ptarmica profile
- USDA PLANTS – Achillea ptarmica
- NC State Cut Flowers Trial – Achillea ptarmica ‘Pearl Reselected’
Written by: Your Flowers Guide editorial team
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