Allium ‘White Giant’

The common name for Alliums is Ornamental Onions. Yes, they're related but we just stick to calling them Alliums and shut up about the onions. They need sun and reasonably well drained and reasonably rich soil. They're hardy but die down in the winter. As soon as the mighty flower appears, the foliage wilts so if you're clever, they'll be planted where you can see the flower but not the base with the wilting leaves. To do clever positioning, it's important to know how tall the flower is likely to get - they vary between 6" and 3ft according to the species. It'll give you some idea on the label. Look out for slugs.