Acanthus hungaricus (Long-leaved bear's breeches): Architectural spires of purple/white flowers over large, dark green deeply divided leaves. Best in sun or light shade. Height to 1.2m [Collect Only]

Campanula 'Kent Belle' (Bellflower 'Kent Belle'): Tall upright stems with deep violet, narrow drooping bell shaped flowers above dark green foliage. May need some support. Hardy. To 1.2m.

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 [Collect Only]

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.

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

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

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.

Salvia nemorosa 'Amethyst' (Balkan Clary 'Amethyst'): Slender spires of long-lasting warm purple spikes from mid to late summer. To 90cm. 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]

Stachys officinalis 'Hummelo' (Betony 'Hummelo'): Upright spikes of rosy purple flowers above pointed dark green foliage. Very attractive to bees. To 50cm. Hardy.

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. [Collect Only]