'White Giant' is a naturally occurring white-flowered form of Allium stipitatum, native from Turkey to the Tien Shan Mountains in Central Asia. Flower spikes grow to 4 feet tall and feature white flowers with a dark green center. Unlike many ornamental onions, the leaves are still green and fresh looking when the plant comes into flower. The key to keeping this and many other ornamental onions long-lasting in the garden are soils that do not stay wet in summer.