Allium giganteum

Allium giganteum, commonly called giant onion, is perhaps the tallest of the ornamental onions. It is a bulbous perennial (large bulbs to 2-3" diameter) which produces a basal rosette of grayish-green, strap-shaped leaves (to 18" long). From the center of each basal rosette rises a thick, naked, 3-4’ tall scape (stem) which is topped in late spring by a dense, globular, softball-sized, 5-6" diameter cluster (umbel) of tiny, star-shaped lilac-purple florets. Leaves and scapes smell like onions when bruised, but plant is not used for culinary purposes. Leaves begin to die back as plants begin flowering.