Alliums are fantastic bulbs with many qualities. The bold often spherical or oval flower heads provide a natural focal point and make a strong arcticetural statement. They can be planted in amongst herbaceous plants or annuals and will happily push their way up through the foliage. So if you don't have a lot of space they won't take up any extra room.
They are excellent for Bees and Butterflies, providing a veritable feast for polinating insects of all types. Alliums are fantastic and extremely trendy cut flowers, lasting well in a vase. Also the seedheads are very decorative and can be spray painted and will last for many years in your home.
All they require is a fairly sunny position and reasonably well drained soil. They can actually grow in dappled shade but the light levels do need to be good. They can do quite well near trees such as Silver Birch which are not to broad and have small leaves which let filtered sunlight through to the ground.