Amsonia hubrichtii (Hubricht's bluestar):
Clumps of soft feathery green foliage and palest blue star-like flowers in late Spring. Textural plant. Attractive autumn colour. Up to 60cm. Hardy
Cynoglossum nervosum (Himalayan hound's tongue):
Upright stems of clear blue flowers, like Forget-me-not, bright green hairy, lance-shaped leaves. Needs sun and well-drained soil. Hardy. Up to 60cm.
Scabiosa caucasica 'Stafa' (Scabious 'Stafa'):
A darker blue form of the classic large cornflower blue frilled scabious flowers over lance-shaped grey-green foliage. Height to 60cm. Hardy.
Veronica gentianoides (Gentian Speedwell):
Short spikes of pale-blue flowers above rosettes of evergreen glossy leaves. Good for the edge of a border. Hardy. Up to 45cm.