upright vertical stems, airy heads of mauve. 100 to 150cm. Very atractive to butterflies - even the odd silver washed fritillaries with us. Unless your soil is very heavy it will seed around so that even if the parent dies, babies will pop up. Generally hardy in Britain. Provides a very long season of interest and structure from midsummer. We leave the stems standing til end of winter and the tits make good use of the seeds.