Allium giganteum (giant onion)

Japanese name: アリウム ギガンテウム
Scientific name: Allium giganteum

[Overview]
A perennial that forms a bulb underground.
The bulb is large and egg-shaped, 5–7 cm across.
When the stem or leaves are damaged, they give off an onion-like smell.
The leaves are basal, flat and strap-shaped, about 50 cm long, and gray-green.
The leaves begin to wither at flowering time.
An erect flower stalk 1–1.5 m tall bears a spherical umbel 10–15 cm across at its tip, densely packed with flowers.
The inflorescence is at first enclosed in bracts.
The flowers are reddish purple, with 6 tepals that open in a star shape, and the stamens protrude out of the flower.
The fruit is a capsule.

[Cultivation]
Propagate from seed; it takes several years from sowing to flowering.
The bulbs do not multiply readily, but division of bulbs is also possible.
It dislikes acidic soil.
It prefers sunny, well-drained soil.
Take care that it does not become extremely dry; during the growing season, 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 tall, so plant it in a place sheltered from strong winds or set up stakes.
If you are not collecting seed, cut the flower stalk at its base once the flowers are finished so that the plant does not become exhausted.
When the leaves begin to wither, dig up the bulbs and store them in a well-ventilated shady place.
If the site is sunny and well drained, pests and diseases hardly occur.

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