Horticultural Highlight: Millenium Ornamental Onion, Allium ‘Millenium’
…Something in me isn’t ready
to let go of summer so easily. To destroy
what I’ve carefully cultivated all these months…
The common onion, Allium cepa would not make many lists of beautiful ornamental plants. Nor would the garlic, Allium sativum, chives, Allium schoenoprasum, or leeks, Allium ampeloprasum. All are members of the large genus Allium, which depending on taxonomic interpretation include 750 or 850 or more species, primarily native to the temperate climates of the Northern Hemisphere. In historic times this genus’ place was in the kitchen or vegetable garden. In our modern era people began to know the “ornamental onions.” You will find in many nursery catalogues as well as landscapes, ornamental Allium species with exceptional beauty.
One well-known, striking example is the hybrid ‘Globemaster’, with its three-foot tall stems topped with large purple flowerheads. You may recall these from their earlier June display around our flagpole planting bed.
Allium ‘Millenium’ one of the more recent horticultural hybrid ornamental onions blooms during mid-to-late summer. This 10-15-inch, compact, upright clump, of dark-green, grass-like leaves is topped with 2-inch, rose-purple balls of florets.
This summer floral display may last four to six weeks, attracting many bees, butterflies and other pollinators. When the colorful florets wilt they dry to a tan color still providing texture and accent in the garden. Additionally, this is a drought-tolerant perennial that rabbits and deer leave alone.
Bred by Mark McDonough, a Massachusetts plant researcher, who specializes in growing and selecting Alliums, this was selected by the Perennial Plant Association as the Perennial Plant of the Year for 2018. On your next visit to Mount Auburn look for Allium ‘Millenium’ within our new Asa Gray Garden, just inside our main entrance.