Several years ago, I saw Allium (Ornamental Onion) in bloom at the Daniel Stowe Botanical Garden. It was a first for me, and I was immediately smitten by the softball-sized purple flowers on tall stems, floating above the surrounding plants. They looked almost other-worldly. I ordered Allium giganteum bulbs and planted them in my own garden.
Allium in a mixed bed at Daniel Stowe Botanical Garden, Belmont NC. It is now known at the Daniel Stowe Conservancy.
The first thing I learned was that tall flowers on skinny stems need to be staked in areas with frequent summer thunderstorms. I hate staking. The second thing I learned was Allium are not long-lived bulbs, or at least they were not for me. By the fourth year, my planting had dwindled down to a single bulb reappearance. By year five they were entirely gone. I was disappointed, but not every plant will thrive in every garden. I decided against replanting them.
Then, Proven Winners™ introduced ‘Millenium’ Ornamental Onion. The garden world was abuzz with enthusiasm, and in 2018 it was named Plant of the Year by the Perennial Plant Association. Millenium’s shorter height – just 15 to 20 inches – means no staking. It is adaptable to different soil types, neutral or acidic. It is hardy in zone 4 through 9. All Alliums are deer resistant and are rarely bothered by insects or diseases. Give them full sun. They are drought tolerant.
Although they are bulbs, ‘Millenium’ Alliums are not usually sold as bare bulbs but as potted plants in leaf, like other perennials. Marketing photographs of them show large clusters of rosy purple flowers. They look a bit like Chives on steroids. I added a few to my garden and waited. The first year I had foliage only. The second year, a paltry few flowers appeared. This year, though, my patience was repaid with a beautiful floral show beginnng in July. The fragrant flowers have lasted weeks and weeks. Bees and butterflies love them. They would work well in containers also. If you prefer the taller Allium, there are numerous cultivars available via specialty bulb nurseries.
This photo of Millenium Ornamental Onion is from the Proven Winners website. Here is a link to their page: https://www.provenwinners.com/plants/allium/millenium-ornamental-onion-allium-hybrid