Sprays of purple flowers on long, strong stems. A long-flowering perennial for the back of a border, producing a beautifully airy display that will last throughout summer and autumn. Flowers are enhanced by the deep coloured stems. Flowers June-October.
Sow the seed 13mm (1/2″) deep direct into a finely raked, moist, warm, weed-free seed bed. Germination usually takes 40-50 days. As the seedlings develop, thin them gradually to achieve a spacing of 15cm (6″) apart. Transfer your young plants to a site in full sun in autumn for flowering the following year spacing the plants 30cm (12″) apart.