While some allium flowerheads are just a couple of centimetres wide, others can be ten times as large. These perennials range in height from 15 centimetres to more than a metre, with flower colours of white, yellow, blue, silvery pink and mauve. Their leaves (either round and hollow or flat and strap-like), although attractive when they first emerge, can become untidy later in the season. Plant them among other perennials or annuals such as roses, irises, poppies, anemones or petunias to help screen the leaves.
Alliums are long-lived and do not appeal to deer, squirrels, rabbits, mice or chipmunks. Flowers can be left on the stalk to dry or, if cut early, will last up to three weeks in water. The slightly garlicky smell they emit when cut disappears once put in water.