Salvia corrugata - 1m x 1m - Corrugata has gorgeous cobalt blue flowers in the warmer months of the year. Also worth noting is its leathery textured foliage. Ideal for perennial borders, Salvias are a riot of colour from spring through to autumn. A good pruning after flowering will ensure strong bushy regrowth for the next season. It is suitable for a full sun to part shade position, and requires little water once established.