Common Name: ornamental onion
Type: Bulb
Family: Amaryllidaceae
Zone: 4 to 8
Height: 3.00 to 4.00 feet
Spread: 0.50 to 0.75 feet
Bloom Time: May
Bloom Description: Purple
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy
Leaf: Fragrant
Attracts: Butterflies
Tolerate: Deer, Drought, Black Walnut
Culture
Easily grown in average, dry to medium moisture, well-drained soils in full sun to part shade. Best in full sun, but appreciates some light afternoon shade in hot summer climates. Tolerates a wide range of soils. Performs well in sandy soils. Add compost to clay soils, as needed, to improve drainage. Bulbs are best planted in fall. Deadhead after blooming to discourage unwanted seeding in the garden. Divide in the spring or early fall.
Noteworthy Characteristics
The genus Allium contains over 700 species of bulbous or rhizomatous plants. All possess oniony smelling flowers and foliage. Some species are grown for culinary purposes and others for ornamental purposes. Plants typically produce showy flower umbels on naked scapes rising above a clump of linear grass-like leaves. Ornamental alliums generally range in height from 3” to 4-6’ tall.
Genus name comes from the classical Latin name for garlic.
‘Ambassador’ is a new giant cultivar that produces perfectly round 6 inch spheres of rich purple florets. Standing tall at 3-4 feet on well supported stems these blooms provide a strong vertical scape for borders from late spring to early summer.
Problems
Bulb rot may occur in overly moist soils. Watch for mildew, rust and leaf spots. Thrips are an occasional problem. Deer and rabbits tend to avoid this plant.
Uses
Grow as a striking accent.