Vinca major (bigleaf periwinkle, "Tsurunichinichiso")

Japanese name: ツルニチニチソウ （蔓日日草）
Scientific name: Vinca major

[Overview]
An evergreen perennial or subshrub about 25 cm tall.
In cold regions it is semi-evergreen.
Many stems emerge from the base of the plant; at first they stand upright, but gradually they creep along the ground and spread.
Flowering stems grow 40–50 cm, and non-flowering stems grow over 1 m.
Leaves are simple and opposite, ovate to ovate-lanceolate, 3–9 cm long and 2–6 cm wide, with a glossy upper surface.
It resembles Hime-tsurunichinichiso, but is characterized by hairs on the leaf margins.
The flowers are borne singly in the leaf axils, 4–5 cm across and pale purple.
The corolla is tubular, with the tip divided into 5 lobes twisted in one direction.
The fruit is a cylindrical follicle.

[Uses]
The whole plant is poisonous, but it is used medicinally.

[Cultivation]
Propagate by division or by stem cuttings.
In cold regions the leaves are damaged, so protecting the plant from cold, for example with frost covers, lets you enjoy the leaf color for a long time.
It grows well from sun to shade and prefers fertile soil with good drainage and aeration.
It flowers better in the sun, but variegated cultivars scorch easily in strong direct summer sun, so partial shade is better.
Take care not to overwater; for potted plants, water thoroughly when the soil dries, and for plants in the ground, once the roots are well established, rainfall is sufficient.
If fertilizer is applied at planting, no further fertilizing is particularly necessary.
If a variegated cultivar produces branches bearing only plain green leaves, this is a reversion to the original species, so cut off the whole branch.
There are no particular pests or diseases.

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