Agastache 'Blue Boa' (PBR) (giant hyssop 'Blue Boa'): Excellent new form of Agastache with much fatter spikes of vibrant purple-blue flowers, with aromatic foliage. Hardy. Up to 80cm.

Angelica gigas: Magnificent plant with huge domes of purple flowers in summer, and attractive seed heads. Biennial/short-lived perennial. Up to 2m.

Astrantia major 'Abbey Road' (PBR) (Hattie's pincushion, Masterwort 'Abbey Road'): Dark red flowers on dark almost-black stems above green foliage. Grow in damp soil and good light for best colour. Long-flowering. Hardy. Up to 80cm. [Collect Only]

Campanula Iridescent Bells = 'Iribella' (PBR) (Bellflower 'Iridescent Bells'): Purple buds open to silvery-lilac bells in summer. Prefers a moisture retentive soil. Height to 80cm. Hardy

Centaurea 'Jordy' (Perennial cornflower 'Jordy'): Beautiful maroon-purple flowers over felty silvery-green foliage.

Centaurea montana 'Parham' (Perennial cornflower 'Parham'): Large lavender purple fluffy flowers over silvery-green foliage. To 40cm. Hardy

Centaurea montana 'Violetta (Perennial cornflower 'Violetta'): Large purple cornflower-like flowers over grey-green foliage. Very attractive to bees and butterflies. Up to 40cm. Hardy.

Cirsium rivulare 'Trevor's Felley Find' (PBR) (Syn. C. rivulare 'Trevor's Blue Wonder'): Not blue at all, I'm afraid, but a more purplish hued form of the more familiar deepest pink Cirsium rivulare 'Atropurpureum'. Hardy. To 1.5m

Echinacea purpurea 'Green Twister' (Coneflower 'Green Twister'): A new variety with a unusual mix of purple and lime green flowers with upturned petals and a central dark cone. Hardy. Up to 60cm.

Erigeron 'Adria' (Fleabane 'Adria'): Mound forming perennial forming masses of semi-double purple flowers with central yellow disc. Hardy. Up to 60cm.

Erigeron 'Dunkelste Aller' (Fleabane 'Darkest of all'): Large purple daisy flowers over a long season in summer. Great in sunny, dry borders. To 30cm. Hardy [Collect Only]

Festuca amethystina: Evergreen grass with elegant, dusky purple arching flower stalks very early in season, for a grass.

Geranium maculatum 'Beth Chatto' (Spotted cranesbill 'Beth Chatto'): Very pretty palest purple flowers held above attractive green foliage. To 50cm. Hardy.

Geranium maculatum 'Vickie Lynn' (Spotted cranesbill 'Vickie Lynn'): Pale lavender flowers above a clump of fresh green divided leaves. Prefers soil that doesn't dry out in summer. Hardy. Up to 45cm.

Geranium phaeum (Dusky cranesbill): Purple flowers with swept-back petals held high above soft green foliage. Early to flower, reliable and easy. To 60cm. Hardy.

Geranium phaeum 'Lily Lovell' (Dusky cranesbill 'Lily Lovell'): Large, rich purple flowers with white centre. Petals swept back. Hardy. Flowers early in the season. To 80cm.

Geranium phaeum 'Raven' (Dusky cranesbill 'Raven'): Dark purple flowers with long stamens and swept-back petals held high above soft green foliage. Great for shady areas. To 60cm. Hardy. [Collect Only]

Geranium phaeum pale purple (Dusky cranesbill pale purple): Pale purple flowers with swept-back petals held high above soft green foliage. Early to flower, reliable and easy.

Geranium pratense 'Dark Reiter' (Meadow cranesbill 'Dark Reiter'): Dark purple/bronze leaves with single purple flowers in mid-summer. To 40cm. Hardy

Geranium pyrenaicum 'Bill Wallis' (Mountain cranesbill 'Bill Wallis'): Masses of tiny purple flowers, good for ground cover

Geranium wlassovianum: Warm purple flowers over attractive velvety foliage. Excellent autumn foliage colour.

Hosta 'Devon Green': Elegant hosta with tapering, dark green, fine-veined leaves. Lilac flowers in summer

Hosta 'Empress Wu' (PBR): One of the largest leaved Hostas in cultivation - possibly the largest. Leaves up to 18" across when established. [Collect Only]

Hosta 'Praying Hands': Very upright, rippled leaves. Leaves are green, narrowly edged in white and curl up. Lilac flowers in summer. Hardy. Up to 40cm. AGM.

Iris 'Langport Wren': Sword-shaped glaucous green leaves and stems of up to 4 flowers, with rich reddish-purple and deep maroon almost brown flowers. [Collect Only]

Lathyrus vernus (Spring pea): Two-tone purple and pink pea-like flowers in early spring. Thrives in shade, even quite dry shade. To 30cm. Hardy.

Liatris spicata 'Kobold' (Gayfeather 'Kobold'): Plump spikes of purple flowers in mid to late summer. Likes dryish soil in a sunny spot. To 80cm. Hardy [Collect Only]

Liriope muscari 'Big Blue' (Blue turf lily 'Big Blue'): Spikes of vibrant purple flowers in autumn, larger than the usual form, evergreen strappy foliage. Good for dry shade. Hardy. Up to 50cm

Molinia caerulea 'Transparent' (Purple moor grass 'Transparent'): Deciduous grass with long feathery purple flower spikes. Likes moist but well-drained soil in sun or light shade. Hardy. Up to 1.2m.

Ophiopogon planescapus 'Nigrescens' (Black lilyturf): Jet back strappy leaves and purplish flowers in mid-summer. Widely and rightly used in modern planting schemes against silvery plants and paving.

Perovskia 'Blue Spire' (Russian Sage 'Blue Spire'): Fine spikes of purple flowers on silver stems. Lovely winter stem effect. Hardy. Up to 1m.

Pulsatilla vulgaris 'Papageno' (Pasque flower 'Papageno'): The petals are deeply dissected, giving a frilled, double effect. Usually purple but can be pink, reddish or white. Hardy. To 30cm

Salvia nemorosa 'Caradonna' (Balkan Clary 'Caradonna'): Rich purple spikes in early summer - just in time for Chelsea Flower Show at which is widely used.To 50cm. Hardy

Salvia nemorosa 'Ostfriesland' (Balkan Clary 'Ostfriesland'): Masses of upright spikes of purple flowers in mid summer. Easy and trouble free. To 50cm. Hardy

Salvia verticillata 'Purple Rain' (Whorled Clary 'Purple Rain'): Purple flowers on slightly arching stems above soft, grey-green leaves. Hardy. To 60cm. [Collect Only]

Salvia x sylvestris 'Mainacht' (Wood sage 'May Night'): Spikes of warm purplish blue flowers in mid-summer. Height to 70cm. Hardy. [Collect Only]

Thalictrum 'Splendide' (Rue 'Splendide'): Superb Thalictrum with clouds of purple flowers open for a very long time in late summer. Hardy. Up to 1.5m [Collect Only]

Verbena bonariensis: Tall, airy but strong slender stems with flat heads of purple flowers in mid to late summer. To 1.8m. Frost-hardy.

Veronica 'Purpleicious Harmony' (PBR) (Spiked speedwell 'Purpleicious'): Spikes of dark-purple flowers over a mound of shiny green leaves. Long-flowering and excellent as a cut flower. Hardy. Up to 50cm. [Collect Only]

Veronicastrum virginicum 'Fascination' (Culver's Root 'Fascination'): One of the best cultivars with tall tapering spires of warm purple/blue flowers in mid-summer. To 1.8m. Hardy.

Vinca minor 'Atropurpurea' (Small periwinkle 'Atropurpurea'): A compact mat-forming evergreen perennial with trailing stems of dark green leaves and dark purple flowers. Good in shade. Hardy ground cover.