Symphyotrichum novi-belgii (New York aster, "Yuzengiku")

Japanese name: ユウゼンギク （友禅菊）
Scientific name: Symphyotrichum novi-belgii

[Overview]
A perennial about 20–180 cm tall.
The stem is erect and branches freely in the upper part.
There are basal leaves and stem leaves; the basal leaves and the lower stem leaves have withered by flowering time.
The stem leaves are simple and alternate, densely arranged up to the stem tip, 5–15 cm long and about 1–2.5 cm, linear-elliptic to ovate-lanceolate, and somewhat thick.
The leaf margins are entire or have low teeth.
Many flower heads are borne in corymbs at the stem tips; most are about 2.5 cm across and consist of ray florets and tubular florets.
There are 20–50 ray florets, in colors such as white, purple, bluish purple, pink and red.
The fruit is an achene with a pappus.

[History]
It was introduced to Japan as an ornamental in the Taisho era.

[Cultivation]
Propagate by division or by stem cuttings.
It grows well in any soil as long as the site is sunny and well drained.
Take care not to let it become too wet; for potted plants, water thoroughly when the soil surface dries, and for plants in the ground, rainfall is sufficient unless sunny weather continues and the soil dries out.
Too much fertilizer makes it leggy and prone to falling over, so go sparingly; for plants in the ground, fertilizer at planting is enough and nothing more is needed, while for potted plants, you may place slow-release fertilizer on the soil in spring, depending on how the plant is growing.
Cutting it back hard in early summer increases the number of branches and produces more flowers.
Remove spent flowers often.
After flowering, the plant may be cut back.
Stake tall plants.
Powdery mildew, Sclerotinia disease of perennial asters, rust, leafminers and aphids may occur.

[Notes]
The alternate name Mikaerumasu (Mikerumasu) comes from the fact that it flowers around the Christian Feast of Michael, held on September 29.

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