Allium sphaerocephalum (round-headed leek)

Japanese name: 丹頂アリウム
Scientific name: Allium sphaerocephalum

[Overview]
A perennial that forms an egg-shaped bulb underground, with small bulbs around it.
The leaves are basal, slender and tubular, semicircular in cross section.
The leaves begin to wither during the flowering period.
A flower stalk 0.5–0.7 m tall stands erect and bears at its tip a small spherical umbel 1–6 cm across, densely packed with many flowers.
The inflorescence is at first enclosed in bracts.
The flowers are reddish purple and open from the top of the inflorescence downward; there are 6 tepals, which do not open fully but form a tube, and the stamens project out of the flower.
The fruit is a capsule.

[Cultivation]
Propagate from seed or by dividing the bulbs; when grown from seed, it takes several years from sowing to flowering.
It dislikes acidic soil.
It prefers sunny, well-drained soil.
Take care that the soil does not become extremely dry, and during the growing period water thoroughly when the soil surface dries.
Apply base fertilizer, and from spring until flowering give liquid fertilizer once every 2 weeks.
The flower stalks stand up, so plant in a place sheltered from strong wind or set up stakes.
If you are not collecting seed, cut the flower stalk at the base after the flowers finish so that the plant does not become exhausted.
When the leaves begin to wither, dig up the bulbs and store them in shade with good ventilation.
If the site is sunny and well drained, pests and diseases rarely occur.

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