Lavandula angustifolia 'Princess Blue'

A shrub up to 50cm high, occasionally up to 75 cm high, with an erect compact habit when young, less so when older, evergreen, aromatic, linear grey-green leaves 4-5cm long, and flowering stems up to 38cm long topped by spikes 4-5cm long of fragrant, mid-violet or bright violet-blue flowers in late summer