Globemaster's flower heads may reach as much as 6-10 inches (15 to 20 cm) in diameter, making it a striking accent plant. These impressive blooms are long lasting and created from individual florets in the shape of stars.
Following blooming, flower heads dry and continue to be attractive well into the summer months.
Placing them behind plants with heavy foliage such as Peonies or Iris will produce a lovely scene.
The flower heads are also good for drying. Many gardeners immensely enjoy Allium Globemaster as a naturalized flower.
Gardener's HQ Guide to Growing Ornamental onion
This lovely plant likes full sun but partial shade in the afternoon is a bonus on hot summer days.
It prefers a dry to medium moisture well-drained soil, and will tolerate a wide range of soil types and pH acidities. If your soil is clay, sand may be added to improve drainage.
Ornamental Onion Globemaster does not produce seeds. It is best to plant new bulbs in autumn /fall at 4-6 inches (10 to 15 cm) deep or at three times the diameter of the bulb.
Space Allium Globemaster at about 12 inches (30 cm) apart.
If you require further plants then dig bulbs of established plants to divide and replant in late summer or early fall, be sure to wait until the foliage has died down.
Allium Globemaster Growing and Care Guide
Scientific Name: Allium Globemaster
Common Name: Ornamental Onion
Growing Zone: USA: 5 to 10
Life Cycle / Plant Type: Perennial
Plant Height (Inches): 36 to 60
Plant Spread (Inches): 2 to 12
Time of Bloom: Early summer to Mid summer
Flower Details: Purple
Leaf Foliage: Green
Growth Form: Upright / erect
Ideal Growing Conditions
Best Light Conditions: Full sunlight
Rate of Growth: Quick
Suitable Soil Types: Loamy, Neutral, Sandy, Well drained
Soil Moisture: Moist
Level of Maintenance: Low
Propagation: Seed, sowing in containers in a cold frame when just ripe or in the spring. Alternatively, remove offsets in autumn
How to Prune: Not usually required
Pests: Usually pest free
Diseases: Mainly trouble free, Onion white rot and downy mildew
Can Attract: Butterflies
Tolerant of: Deer, Drought, Black Walnut
Best Garden Use: Container, Foundation, En masse , Rock garden, Specimen
Closely Related Species: Agapanthus, Amarylis, Leucojum, Lycoris, Galanthus, Narcissus, Nerine,Sprekelia, and Zephyranthes.
Miscellaneous: Attractive foliage, Fragrant foliage, Attracts butterflies, Suitable for cut flowers, Suitable for dried flowers