About

Allium 'Globemaster' is a robust perennial characterized by its long, strap-like, grey-green leaves that can reach up to 1 meter in length. In summer, it produces large, spherical clusters of violet-purple flowers, each measuring up to 20 centimeters in diameter, atop stems that grow as tall as 80 centimeters.

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
West-facing, South-facing
Exposure
Sheltered
UK hardiness
H6

Plant details

Plant type
Bulbs
Habit
Clump forming
Foliage
Deciduous
Height
0.5-1 metres
Spread
0.1-0.5 metres
Time to full height
2-5 years
Suggested uses
Cottage and informal garden, City and courtyard gardens, Coastal, Gravel garden, Wildlife gardens
Fragrance
Foliage

Care notes

Cultivation
Easy to grow in fertile well-drained soil. Add grit when grown in clay soils to improve drainage. See allium cultivation for further advice
Pruning
No pruning required
Propagation
Propagate by seed, sowing in containers in a cold frame when just ripe or in the spring. Alternatively, remove offsets in autumn
Pest resistance
Generally pest-free
Disease resistance
Generally disease-free but may be susceptible to onion white rot and downy mildews