The Allium giganteum, also aptly named the giant onion, is a very large allium with huge 120cm stems and massive purple flower heads reaching 6 inches in diameter. The giant onion is best planted late in the year from September to December, it then blooms in early summer around June. The Allium giganteum is also a recipient of the Award of Garden Merit, a testament to the quality of the plant.
The bulbs do best when planted about 10cm deep in well-drained, nutrient-rich soil. Large alliums like this also benefit from shelter on one side to prevent the tall flower spikes from falling over in the wind.
Planting Time: September - December
Flowering Time: June
Max Height: 120cm