Aconitum napellus (Monkshood): Dark blue hooded flowers over finely divided foliage. This Aconitum flowers early, in late spring/early summer. Height to 1.5m. Hardy. [Collect Only]

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.

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

Calamintha nepeta 'Blue Cloud': Spikes of small, soft blue flowers above mounds of minty scented green leaves. Loved by bees and butterflies. Hardy. Up to 30cm.

Campanula lactiflora 'Prichards Variety' (Milky bellflower 'Prichards Variety'): Clusters of warm blue flowers on tall stems in mid-summer. To 1m. Hardy. [Collect Only]

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

Centaurea montana 'Grandiflora' (Perennial cornflower 'Grandiflora'): Larger blue flowers than the species, with darker purple heart in early summer, cut back for repeat flowering. Very attractive to bees. To 50cm. Hardy

Ceratostigma plumbaginoides (Plumbago, Hardy plumbago, dwarf plumbago): Brilliant blue flowers in later summer over foliage which turns redder as winter approaches. Stunning ground cover plant for sheltered spots. Not fully hardy in colder parts of UK. To 20cm. Frost-hardy [Collect Only]

Cichorium intybus (Wild chicory): Beautiful cornflower-blue flowers held on tall stems in late summer. The flowers appear dotted all along the stems in succession through late summer and early autumn. To 2m [Collect Only]

Corydalis elata: Summer flowering Corydalis with bright blue flowers above soft green foliage. Excellent in some shade in moist soil. Hardy. Up to 30cm.

Echinops bannaticus 'Blue Globe' (Globe thistle): Tall upright stems of bright blue globe flowers above clumps of spiny, grey-green leaves. Bee-friendly. Hardy. Up to 1.2m. [Collect Only]

Echinops bannaticus 'Taplow Blue' (Globe thistle): Tall stems of pale blue globe flowers, clumps of spiny, grey-green leaves with silver undersides. Bee-friendly. Hardy. Up to 1.5m.

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.

Eryngium bourgatii 'Picos Amethyst'': Stunning steely blue flowers on stiff stems with a gorgeous purple tint. Loves sunshine and well-drained soil. To 70cm.

Eryngium x zabelii 'Big Blue (Sea Holly 'Big Blue): Large electric-blue thimble-shaped flowers with a spiky collar and silver-green foliage. Long flowering and bee-friendly. Hardy. Up to 75cm [Collect Only]

Eryngium x zabelii 'Jos Eijking' (Sea Holly 'Jos Eijking'): Large steely blue bracts surround a dome of tiny blue flowers in summer. Long-lasting flowers.Thrives in a sunny,dry spot. To 70cm. Hardy. [Collect Only]

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.

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 [Collect Only]

Lobelia siphilitica (Blue cardinal flower): Tall spikes of clear blue flowers and bright green lance-shaped leaves. Needs a soil which doesn't dry out. Hardy. Up to 90cm.

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 racemosa 'Walker's Low' (Catmint 'Walker's Low'): Forms neat mounds of silvery green foliage, topped with masses of lavender blue flowers in early summer. Up to 60cm. Hardy.

Nepeta x faasenii (Catmint): A compact variety of catmint with mounds of aromatic silvery green foliage and lavender blue flowers.Hardy. Up to 45cm.

Pulmonaria 'Trevi Fountain' (Lungwort 'Trevi Fountain'): Long flowering, with blue flowers over silver-speckled leaves in spring. Great in shade. Hardy. Height to 30cm.

Salvia patens 'Cambridge Blue': Beautiful Salvia with pale blue two-lipped flowers flowering in late summer. Needs a sunny, sheltered position and protect with mulch.To 1m. [Collect Only]

Salvia uliginosa (Bog Sage): Branched stems of clear blue flowers and lance-shaped leaves. Needs a sunny spot but with moist soil. Late flowering. To 2m.

Veronica austriaca 'Crater Lake Blue' (Speedwell 'Crater Lake Blue'): Vivid blue spikes above a mound of green foliage.To 30cm. Hardy.