White Giant Allium

White Giant Ornamental Onion (Allium stipitatum ‘White Giant’) impresses with its large, pure white spherical flower clusters carried on tall, sturdy stems reaching 100 to 120 cm in height. Blooming from May to June, it brightens flower beds and creates an elegant vertical presence, especially striking alongside purple alliums and colourful perennials. Its blue-green strap-like foliage adds attractive early-season interest before naturally turning yellow after flowering. Hardy to Zone 4, this bulbous perennial performs well in Canadian gardens when planted in perfectly drained soil.

Plant the bulbs in fall at a depth of 15 to 20 cm, spacing them 20 to 30 cm apart. ‘White Giant’ prefers full sun and light, fertile, perfectly drained soil with a neutral to slightly alkaline pH. Water lightly after planting, then moderately during active growth, allowing the soil to dry between waterings. Once established, this allium tolerates dry periods well. A light application of compost in spring is generally sufficient. After flowering, allow the foliage to turn completely yellow before cutting it back so the bulbs can replenish their reserves.

Perfect for large flower beds, contemporary gardens, naturalistic plantings, and pollinator gardens, this allium pairs beautifully with peonies, sage, catmint, irises, and ornamental grasses. Its enormous white flower spheres add structure, brightness, and refinement to garden compositions. Rich in nectar, the flowers attract bees, butterflies, and many other beneficial insects, helping support garden biodiversity. The flower clusters are also exceptional in fresh or dried bouquets and retain their decorative value for several months.