We have found 13 plants that meet your criteria.

Price Pruned
Lavender ‘Lavandula angustifolia Munstead’ A compact variety with blue-purple flowers NOW £5.49 Buy
Russian Sage ‘Perovskia Blue Spire’ Violet-blue flowers and silvery foliage. Great planted en masse £7.99 Buy
Price Pruned
Butterfly Bush ‘Buddleja Lochinch’ Fragrant violet-blue flowers all summer NOW £5.99 Buy
Californian Lilac ‘Ceanothus Autumnal Blue’ Sky-blue flowers in late summer £7.99 Buy
Californian Lilac ‘Ceanothus Burkwoodii’ Bright blue flowers in summer £8.99 Buy
Californian Lilac ‘Ceanothus Concha’ Masses of deep blue flowers in spring £6.99 Buy
Californian Lilac ‘Ceanothus Puget Blue’ Fabulous deep blue flowers £6.99 Buy
Californian Lilac ‘Ceanothus thyrsiflorus Skylark’ A haze of bright blue flowers in early summer £8.99 Buy
Creeping Blueblossom ‘Ceanothus thyrsiflorus var. repens’ A low-growing evergreen with blue flowers £8.99 Buy
Price Pruned
Lavender ‘Lavandula angustifolia Elizabeth’ A new variety, with violet flowers NOW £4.99 Buy
Russian Sage ‘Perovskia abrotanoides’ Silvery white aromatic foliage with long lasting blue flowers £7.99 Buy
Common Lilac ‘Syringa vulgaris Katherine Havemeyer’ Wonderful scented lavender-purple flowers £9.99 Buy
Price Pruned
Russian Sage ‘Perovskia atriplicifolia Little Spire’ A shorter form of the popular Russian sage NOW £7.99 coming soon