Salvia transsylvanica 'Blue Cloud'
(Transsylvanian sage). Hardy perennial forming basal rosettes of large, slightly crinkly dark green leaves. Multiple, branched flower stems carrying whorls of gorgeous deep blue flowers appear over several months in summer. Prefers full sun and average soil, and is drought tolerant once established. Deadhead to prolong flowering. H 70-90cm, W 60cm. 1 litre pot.