Perovskia atriplicifolia ''Blue Spire''
Also known as ''Blue Spike''. A beautiful very hardy perennial sub-shrub (so named because of it's deciduous nature in winter), this gorgeous creature has silvery stems and aromatic greyish foliage which is smothered in small violet-blue flowers from late summer until the first frost. Cut back by a third after flowering as this helps ensure it doesn't become straggly. It can be slow to establish but once it is, you will enjoy it for years to come. Sun, well-drained soil. Tolerates dry conditions really well. 1.5x1m approximately.