We have found 23 plants that meet your criteria.

Price Pruned
Yarrow ‘Achillea millefolium Lilac Beauty’ An unusual lilac, yarrow NOW £5.49 Buy
Erigeron ‘Erigeron Dunkelste Aller (Darkest of All)’ Large dark violet daisies £6.99 Buy
Price Pruned
Bergamot ‘Monarda Ou Charm’ Pretty, pink flowers and purple bracts NOW £5.49 Buy
Catmint ‘Nepeta x faassenii Kit Cat’ A dwarf variety with purple flowers £5.99 Buy
Phlox ‘Phlox paniculata Franz Schubert’ Wonderful, fragrant, lilac flowers £5.99 Buy
Salvia ‘Salvia nemorosa Amethyst’ Lilac-purple spires of flowers £5.99 Buy
Michaelmas Daisy ‘Aster sedifolius nanus’ A small plant that has big impact £5.99 Buy
Masterwort ‘Astrantia major Rubra’ Gorgeous plum-coloured flowers £5.99 Buy
Cardoon ‘Cynara cardunculus Cardy’ A fabulous architectural plant £5.99 Buy
Stinking Gladwyn ‘Iris foetidissima’ Bright orange berries. Useful for dry shade £5.99 Buy
Giant Catmint ‘Nepeta grandiflora Wild Cat’ A giant catmint with deep purple-blue flowers £5.99 Buy
Price Pruned
Beard Tongue ‘Penstemon Raven’ Dramatic, deep purple, foxglove-like flowers NOW £5.49 Buy
Perennial Phlox ‘Phlox paniculata Amethyst’ Tall variety with violet flowers £5.99 Buy
Price Pruned
Jacob's Ladder ‘Polemonium caeruleum’ Bell-shaped, lavender-blue flowers in early summer. NOW £4.99 Buy
Salvia ‘Salvia nemorosa Caradonna’ Dazzling purple blooms £5.99 Buy
Sage ‘Salvia nemorosa Ostfriesland’ Attractive to butterflies and bees £5.99 Buy
Stonecrop ‘Sedum telephium (Atropurpureum Group) Purple Emperor’ Fabulous variety with gorgeous deep bronze-purple foliage £6.99 Buy
Price Pruned
Sweet Violet ‘Viola odorata’ Sweetly fragrant flowers NOW £4.99 Buy
Wood Violet (syn. Viola labradonica... ‘Viola riviniana Purpurea Group’ Ideal for a woodland garden £4.99 Buy
Wildflower Plug Plant Collection ‘Wildflowers for a boggy meadow’ A collection of 104... £79.99 Buy