We have found 16 plants that meet your criteria.

Price Pruned
Agastache 'Blue Fortune' Mexican Giant Hyssop Spires of lilac flowers and aromatic leaves NOW £5.37 Buy
Nepeta subsessilis 'Cool Cat' Catmint Lavender-blue flowers. Great for a herb garden £5.86 Buy
Nepeta subsessilis 'Washfield' Catmint Pretty catmint with bright blue flowers £5.86 Buy
Nepeta x faassenii Catmint Loose drifts of lavender flowers. Great for edging £5.86 Buy
Nepeta x faassenii 'Kit Cat' Catmint A dwarf variety with purple flowers £5.86 Buy
Price Pruned
Nepeta 'Six Hills Giant' Catmint A hardy catmint with lavender flowers NOW £4.88 Buy
Perovskia abrotanoides Russian Sage Silvery white aromatic foliage with long lasting blue flowers £7.82 Buy
Price Pruned
Phlox divaricata 'Blue Perfume' Phlox Masses of lilac-blue fragrant blooms NOW £5.37 Buy
Price Pruned
Phlox paniculata 'Blue Paradise' Perennial Phlox Fragrant violet flowers all summer NOW £5.37 Buy
Syringa vulgaris 'Katherine Havemeyer' Common Lilac Wonderful scented lavender-purple flowers £9.78 Buy
Buddleja 'Lochinch' Butterfly Bush Fragrant violet-blue flowers all summer £6.84 Buy
Clematis 'Betty Corning' Clematis (Group 3) Pale lilac nodding bells with a delicate fragrance £8.80 Buy
Nepeta grandiflora 'Wild Cat' Giant Catmint A giant catmint with deep purple-blue flowers £5.86 Buy
Nepeta racemosa 'Walker's Low' Catnip Long flowering period £5.86 Buy
Perovskia 'Blue Spire' Russian Sage Violet-blue flowers and silvery foliage. Great planted en masse £7.82 Buy
Price Pruned
Viola odorata Sweet Violet Sweetly fragrant flowers NOW £4.88 Buy