Lavender-Pink. Allium Millennium has a round pompon head of loose flowers held in clusters, it has a neat clump-forming habit which develops the longer they are left in place, this excellent allium will extend the allium flowering season, Millennium flowers in mid-summer, the flowers are held just above the grassy foliage on strong stems, perfect for attracting pollinators especially bees and butterflies, ideal for cut flowers and planting in clumps or mix through hardy perennial plants.