Salvia greggii 'Blue Note' has blue-purple flowers blooming all summer, fragrant foliage and prefers hot dry spots.

Salvia gauranitica 'Black and Bloom' Nectar Blue is an improved, earlier blooming form of 'Black and Blue' with vibrant cobalt blue flowers with black sepals.

Salvia 'Black and Blue' produces truly vibrant cobalt blue flowers with black sepals by the thousands all season long.

Salvia guaranitica Bodacious 'Hummingbird Falls' is a trailing sage perfect for hanging baskets and hungry hummingbirds.

Salvia 'Blue Marvel' has neat and tidy spires of purple buds and blue flowers.

Salvia 'Crystal Blue' offers a unique new colour for perennial sages with sky blue flowers.

Salvia reptans 'Autumn Sapphire' is a compact, late season cultivar with cobalt blue flowers and fragrant, willowy foliage.

Salvia Color Spires 'Azure Snow' has fragrant, two-lipped, bi-colour flowers in violet-blue and white with aromatic foliage.

Salvia 'Violet Riot' has fragrant two-lipped flowers in violet-blue with dark purple sepals and aromatic, green foliage.

Scabiosa Flutter 'Deep Blue' has larger, deeper blue flowers than 'Butterfly Blue'. Popular with butterflies.

Scilla hyacinthoides 'Blue Arrow' looks like a rocket ship of starry blue flowers erupting from out of the border.

Scilla mischtschenkoana blooms early with palest blue, starry, bell-shaped flowers with royal blue midribs.

Portuguese squill, Scilla peruviana, has strap-like leaves and an exotic dome of small, star-like, royal blue to purple-blue flowers.

Scilla siberica is an easy and extremely hardy beauty with glowing blue, starry, bell-shaped flowers with royal blue midribs and dark blue pollen!

Sisyrinchium angustifolium 'Lucerne' has large, bright blue, star-shaped flowers with yellow centres atop grass-like foliage.

Sisyrinchium idahoense, the Idaho blue-eyed grass, has small iris-like foliage and cheerful star-shaped blue flowers.

Sisyrinchium nashii 'Suwannee' is a blue-eyed grass with small iris-like foliage and cheerful starry sky blue flowers.

Streptocarpus 'Harlequin Blue' is a Cape primrose and relative of the African violet with bi-coloured flowers of lavender-blue and yellow.

A neat clump-forming comfrey with light green crinkled leaves. The blue flowers fade gradually to light blue.