Amsonia tabernaemontana (Blue dogbane): Starry blue flowers on strong stems with willowy green leaves. Hardy. Up to 90cm.

Aster x frikartii 'Monch': Soft lavender blue flowers in late summer.Very early flowering and shorter than many asters at about 80cm. Easy and reliable. Hardy.

Geranium 'Blue Cloud' (Cranesbill 'Blue Cloud'): Tall cultivar with pale blue flowers & dark purple veining above deeply divided green leaves. Long-flowering. Hardy. Up to 90cm. [Collect Only]

Geranium pratense 'Cloud Nine' (Meadow cranesbill 'Cloud Nine'): An attractive double form of the familiar meadow cranesbill with lovely soft blue flowers. Strong growing. Hardy. Up to 90cm. [Collect Only]

Iris sibirica (Siberian Iris): Soft, purplish blue iris flowers over strappy green foliage. [Collect Only]

Iris sibirica 'Perry's Blue' (Siberian Iris 'Perry's Blue'): Lovely pale-blue flowers with white markings over strappy green foliage. Prefers moist soil. Makes a bold clump. Hardy. Up to 85cm.