We have found 13 plants that meet your criteria.

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