Perovskia ‘Blue Spire’ is a deciduous small shrub that grows to about 1.2 metres and spreads to around half a metre. Commonly known as ‘Russian Sage’, the plants have deeply-divided aromatic green-grey leaves and white stems. They flower with small, bold tubular flowers from now until late summer. They like full sun with some shelter in well-drained soil. It is good practice to prune them in late winter to just four buds; this will keep them from getting too large and woody.