Allium caeruleumis a native of Central Asia and is known as a blue globe onion. People seem to be attracted to the color blue — at least as it is displayed by flowers. Name the rarest, most sought after cultivars and species, and there will be a disproportionate number of blue-flowered plants on the list, yet they are relatively rare in nature.

The flowers onAllium caeruleum (the latter means "blue" in Latin) are about the size of a silver dollar and are held well above the foliage. It is slow to naturalize in the Chicago region, perhaps due to the preponderance of heavy clay soils and the frequency with which gardeners water their flower beds in summer. If at all possible, purchase this plant when in flower to obtain the best color forms. Several commercially available produce inferior lilac-blue or washed out, faded blue flowers.