Sempervivum (genus, houseleeks)

Japanese name: センペルビバム
Scientific name: Sempervivum

[Overview]
A perennial that in its native habitat grows mainly on sunny rocky ground from mountains to the alpine zone.
It produces many offsets and grows in clumps.
It is stemless or has a very short stem.
The leaves are dense and form rosettes; they are obovate to lanceolate, and in many the leaf tips are tinged with reddish purple.
Some turn red in winter.
A flower stalk extends from the center of the rosette and bears a raceme or cyme.
The flowers are 1–2 cm across with 6–30 petals, in colors such as pink, white and pale green.
There are twice as many stamens as petals, and they are 1/2–2/3 the length of the petals.
The plant dies after flowering.
The fruit is a follicle.

[Cultivation]
Propagate from seed, by division, or by stem cuttings.
It prefers a sunny, well-drained, well-ventilated environment.
It is tolerant of cold and frost but dislikes heat and humidity, so place pots on a shelf or similar so air can reach the bottom, and in summer move them to cool, airy partial shade.
During long rainy spells, move it to a place where it will not get rained on.
Keep it on the dry side in summer, and in other seasons water thoroughly when the soil begins to dry.
In spring and autumn, apply a small amount of slow-release chemical fertilizer or liquid fertilizer.
Pests and diseases include aphids and scale insects.

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