Another excellent one for edging beds - and the bees and hoverflies just love it is Hyssop. A small woody bush that can be clipped into a mini-hedge (I have a Hyssop-hedge around my comfrey bed. Bee heaven!), even better it comes in pink, white and blue flowers! Can grow from seed pretty easily, or by plants in pots for a more instant effect!

Lovely with a bit of beef too.......

LCG