Soil: light, moderately fertile, humus-rich, moist but well-drained soil
Rate of growth: average
Flowering period: June and July
Hardiness: fully hardy
A delightful, colourful plant with spikes of indigo-blue flowers in early to midsummer. This reliable perennial is ideal for the middle of a moist, well-drained herbaceous border. It flourishes in sun or dappled shade where the bright flowers help to liven up any plant scheme.
Garden care: To prolong flowering remove the flower spikes as soon they start to fade. Apply a generous 5-7cm (2-3in) mulch of well-rotted garden compost or manure around the base of the plant in spring.