This plant requires a medium level of maintenance to perform at its best, and is particularly suited to US zones 5-8. They prefer warmer temperatures and strong sunlight during the day.
Be sure that soil is well drained but retains a trace of moisture. This will enable the Giant onions to better withdraw the nutrients necessary for proper growth.
If correctly taken care of, these plants can grow to be between three feet and five feet (90 to 150 cm). Allium giganteum grows best when grown in groups, so be sure to arrange them in at least a group of five.
Many gardeners choose these to line their flower beds, due to their columnar nature. They are also great as cut flowers in arrangements and emit a pleasant, leafy fragrance. They add a mysterious aura to a garden and can be used to great effect.
Allium giganteum Growing and Care Guide
Scientific Name: Allium giganteum
Common Name: Giant onion
Growing Zone: USA: 6 to 10
Life Cycle / Plant Type: Herbaceous, Perennial
Plant Height (Inches): 60 to 72
Plant Spread (Inches): 6 to 9
Time of Bloom: Summer
Flower Details: Pink, Purple
Leaf Foliage: Green
Growth Form: Upright / erect
Ideal Growing Conditions
Best Light Conditions: Full sunlight
Rate of Growth: Quick
Suitable Soil Types: Adaptable, Loamy, Sandy, Well drained
Soil Moisture: Moist
Level of Maintenance: Medium
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
Tolerant of: Rabbit, Deer, Black Walnut
Best Garden Use: Container, Foundation, En masse , Rock garden, Specimen
Closely Related Species: Agapanthus, Amarylis, Narcissus, Galanthus, Zephyranthes.
Miscellaneous: Attractive foliage, Fragrant foliage, Non-native to North America, Attracts butterflies, Suitable for cut flowers, Suitable for dried flowers