Allium

This is one of my favourite Alliums, low growing with narrow, tidy semi-evergreen leaves and masses and masses of small lilac flowers all summer. Many other Alliums have foliage that browns and withers when the bulb flower, but that is not the case with Allium senescens. It flowers for such a long time, acting as a magnet for bees and butterflies day after day. Plant it in full sun, in a well drained place, atop a wall or in the rock garden is great. It soon forms a good clump and I use it to the front of lower-growing Crocosmias to set them off.