RHS 
Herbaceous Perennial Annual Biennial
An annual or short-lived perennial with erect, branching stems to 60cm in height and pincushion flowerheads to 5cm across, flowering from midsummer into the autumn. The very dark purple flowers appear almost black, have a delicate scent, and may be followed by bristly seedheads
Position
Full sun
Soil Types
Chalk, Loam, Sand
Max Height
0.5-1 metres
Max Spread
0.1-0.5 metres