Allium ‘Millennium’ has been awarded the 2018 perennial plant of the year. I actually just heard about this plant at a pollinator conference in October from Steve Foltz, director of horticulture at the Cincinnati Zoo and Botanical Garden, who called it a "must-have" plant for the pollinator garden. The zoo has placed it on their Zoo’s Best Perennials for Pollinators list, promoting plants throughout the zoo so homeowners know what to plant in their own yards. The program involves teen volunteers, known as the Buzz Troop, who use cameras to track pollinators to different flowering plants.
“This cultivar of flowering onion is a result of breeding Allium nutans and Allium lusitanicum and was selected for late flowering masses of rose-purple blooms, uniform habit and neat shiny green foliage that remains attractive all season long,” says University of Illinois Extension horticulture educator Martha Smith. Allium “Millennium” is a full sun perennial with leaves growing a foot tall with multiple spherical umbels of florets 18- to 20 inches tall that last about a month. Another attribute making it an outstanding plant is its drought and heat tolerance. In hot summers, it may benefit from afternoon shade, but it requires at least six hours of sun.
Allium ‘Millennium’ is a bulb on a horizontally spreading rhizomatous stem that clumps; gardeners have the option to divide every three to four years after the foliage dies. Alliums are planted in the fall, before the ground freezes, along with other flowering bulbs like tulips and daffodils. Unlike giant alliums that grow three to four feet tall, these Millennium alliums stay compact and are more floriferous. They also have sterile seeds and do not spread like garlic chives. Flowering onions in general are not dug up by voles or squirrels and are not browsed by deer.
Perennial plants of the year must be standouts among their competitors. Generally, they must be sustainable for a wide range of climate conditions, have low maintenance requirements, be relatively disease and pest free, and have multiple seasons of interest. Allium ‘Millennium’ fits all the requirements and is a must-have for the perennial garden.