About

A robust bulbous perennial, Allium 'Round 'n' Purple' features wide, pointed basal leaves of mid-green. The flower stems can reach heights of up to 1.2 meters and are topped with large, 15-centimeter flower heads composed of star-shaped, silvery-lilac blooms that appear in early summer.

About the genus

Allium consists of bulbous herbaceous perennials characterized by a pronounced onion or garlic aroma. They feature linear, strap-like, or cylindrical leaves that arise from the base. The flowers, which can be star-shaped or bell-shaped, are arranged in an umbel atop a stem that lacks leaves.

Growing conditions

Sunlight
Full sun
Soil type
Chalk, Loam, Sand
Soil pH
Acid, Alkaline, Neutral
Soil moisture
Moist but well-drained, Well-drained
Aspect
South-facing, West-facing
Exposure
Sheltered
UK hardiness
H5

Plant details

Plant type
Bulbs
Habit
Clump forming
Foliage
Deciduous
Height
1-1.5 metres
Spread
0.1-0.5 metres
Time to full height
1-2 years
Suggested uses
City and courtyard gardens, Cottage and informal garden, Gravel garden, Wildlife gardens
Fragrance
Foliage
Toxicity
Bulbs may cause skin irritation. Wear gloves and other protective equipment when handling

Care notes

Cultivation
Grow in full sun and fertile well-drained soil. It is best to grow in containers where garden soil is heavy clay and prone to saturation over winter. See allium cultivation
Pruning
No pruning required, other than to remove old flowered stems and foliage
Propagation
Propagate by offsets which can be carefully detached by lifting the bulb after flowering has finished. See bulb propagation
Pest resistance
May be susceptible to allium leaf miner and onion fly
Disease resistance
May be susceptible to onion white rot, and onion downy mildew