Hydrangea hirta (nettle-leaved hydrangea, "Koajisai")

Japanese name: コアジサイ （小紫陽花）
Scientific name: Hydrangea hirta

[Overview]
A deciduous shrub 1–1.5 m tall, found in bright woods and at woodland edges.
It branches freely from the base.
Young branches are tinged with purplish brown.
Leaves are simple and opposite, ovate to obovate, 5–8.5 cm long, with regular, large serrations on the margins.
The leaves are thin, with sparse hairs on both surfaces.
The petiole is 1.2–4 cm long.
Compound corymb-like inflorescences about 5 cm across are produced at the branch tips, bearing only bisexual flowers about 4 mm across.
The bisexual flowers are blue and 5-petaled; the petals curve back and do not fall right away.
There are 10 stamens, which are blue.
The fruit is a round capsule about 2 mm across, with the calyx lobes and style remaining.

[Cultivation]
Propagate from seed or by cuttings.
It prefers moist soil that is well drained and retains water, in sun to partial shade.
It tolerates shade, but flowers less.
It is unsuitable for places where the soil becomes extremely dry or that receive strong afternoon sun.
It absorbs a lot of water, so to prevent it from drying out, water thoroughly when the soil surface of the pot dries.
Apply slow-release chemical fertilizer twice a year, in winter and as a thank-you fertilizer after flowering.
There are no particular pests or diseases.

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