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

Baptisia australis var. minor (Dwarf blue false indigo): A compact form of Baptisia australis. Purple-blue flowers like a lupin with bright green trifoliate leaves. Prefers a sunny spot. Hardy. Up to 50cm

Brunnera macrophylla 'Alexander's Great' (PBR) (Siberian bugloss 'Alexander's Great'): Statement foliage plant for shade. Large, heart-shaped, silver leaves. Light-blue forget-me-not-like flowers in Spring. Hardy. Up to 40cm.

Brunnera macrophylla 'Hadspen Cream' (Siberian bugloss 'Hadspen Cream'): Large, heartshaped green leaves with wide cream margin. Sprays of forget-me-not blue flowers in spring. Hardy. Up to 45cm.

Brunnera macrophylla 'Jack Frost' (PBR) (Siberian bugloss 'Jack Frost'): Large, heartshaped silver leaves with green veins and leaf edges. Sprays of forget-me-not blue flowers in spring.Shade-loving plant. Hardy. Up to 45cm.

Brunnera macrophylla 'Variegata' (Siberian bugloss 'Variegata'): Large, heartshaped leaves with bold variegation. Sprays of forget-me-not blue flowers in spring. Superb shade plant. Hardy. Up to 45cm.

Catananche caerulea (Cupid's dart): Masses of papery lavender blue flowers held on wiry stems all summer. Seed heads turn silver in late summer. Good dried flower. Up to 60cm.

Catananche caerulea 'Major' (Cupid's dart 'Major'): Masses of papery blue flowers held on wiry stems all summer. Seed heads turn silver in late summer.

Centaurea montana (Perennial cornflower): Large blue flowers in early summer, repeated later in year if cut back. Very attractive to bees. To 50cm. Hardy

Eryngium 'Pen Blue' (Sea Holly 'Pen Blue): Electric-blue thistle-like flowers with a spiky collar and silvery-green foliage. Long flowering and attractive to bees. Hardy. Up to 60cm.

Geranium 'Alan Mayes' (Cranesbill 'Alan Mayes'): Long flowering geranium with bright blue flowers with purple veining. Clumps of hairy green leaves, turning red in autumn. Hardy. Up to 45cm.

Geranium 'Brookside' (Cranesbill 'Brookside'): A reliable, robust variety with large rich blue flowers over a mound of deeply divided leaves. Height to 45cm. Hardy

Geranium 'Nimbus' (Cranesbill 'Nimbus'): Makes medium sized domes of finely divided foliage smothered in purplish blue flowers in early summer. To 50cm. Hardy

Geranium 'Orion' (Cranesbill 'Orion'): A dome of deeply divided foliage, smothered in large blue flowers from early summer onwards

Geranium pratense 'Mrs Kendall Clark' (Meadow cranesbill 'Mrs Kendall Clark'): Palest purpley/grey flowers, makes a good mound of foliage. Hardy. To 40cm.

Nepeta 'Six Hills Giant' (Catmint 'Six Hills Giant'): A vigorous sun lover which will soon make a generous clump. Spikes of tiny purple flowers over aromatic grey/green foliage.

Nepeta grandiflora 'Summer Magic' (PBR) (Catmint 'Summer Magic'): A more compact, upright growing variety of Catmint with aromatic grey foliage and spikes of lavender blue flowers. Hardy. Up to 35cm. [Collect Only]

Polemonium reptans 'Stairway to Heaven' (PBR) (Jacob's Ladder 'Stairway to Heaven'): Superb variety with attractive variegated foliage and lavender blue flowers. To 50cm. Hardy

Scabiosa caucasica 'Perfecta Blue' (Scabious 'Perfecta Blue'): Large cornflower blue frilled flowers over lance-shaped grey-green foliage. Height to 60cm. Hardy.

Stokesia laevis 'Purple Parasols' (Stoke's aster 'Purple Parasols'): Large, fluffy purple flowers over slender grey-green foliage. A lovely plant for sunny, well-drained borders. To 40cm. Hardy.

Tricyrtis formosana 'Seiryu' (Toadlily 'Seiryu'): Upright stems of blue star-like flowers, often speckled with lilac and a paler centre. Above dark green spotted foliage. Hardy. Up to 60cm. [Collect Only]