Japanese name: アキレア プタルミカ Scientific name:Achillea ptarmica
[Overview]
A perennial about 45–60 cm tall.
The leaves are simple and alternate, linear to lanceolate, with fine teeth on the margins but not deeply divided.
The leaf bases slightly clasp the stem.
Crushed leaves are fragrant.
Corymb-like inflorescences at the stem tips bear white flower heads.
The flower heads are large, 1–3 cm across, with 12–19 ray florets arranged in 2 rows.
The tubular florets are white.
The involucre is hemispherical, and the involucre and the scales of the receptacle are densely hairy.
The fruit is an achene.
[Cultivation]
Propagate from seed, by division, or by shoot cuttings.
It prefers a sunny, well-drained place.
It is hardy and spreads by extending underground stems, so in a garden it is better to make a frame underground to keep it from spreading too much.
For potted plants, water when the soil surface dries.
No fertilizer is particularly needed.
It dislikes heat and humidity, so keep it well ventilated.
Pests and diseases include aphids, powdery mildew and gray mold.
If the branches become crowded, stuffiness can cause disease.
