(Siberian sage). A hardy species which is also drought tolerant, this was quite a sight in full flower here last summer. Basal clumps of slightly rough looking mid-green leaves. Stout, much-branched stems carry masses of bright violet-blue flowers over a long period in summer. Will repeat flower if cut back and is loved by bees. Full sun to part shade and prefers reasonably free-draining soil. May need staking if you want it upright as it has a tendency to sprawl. 80-120cm x 40-60cm.