Sugar Melt Flowering Onion. There are over 700 species of "Alliums" or onions world wide used both for culinary purposes and for ornament. This is a superb selection with pinkish-lavender flowers atop 12-16 inch tall scapes flowers from July to September. It does well in well-drained soil with full sun. But it might appreciate some light shade in the afternoon. This selection does have viable seed, so to prevent re-seeding in the garden, dead-head the flowers when they fade to prevent any unwanted seedlings. It forms dense clumps which can be divided in early spring or late fall.