Amsonia tabernaemontana (Blue dogbane): Starry blue flowers on strong stems with willowy green leaves. Hardy. Up to 90cm. [Collect Only]

Aster macrophyllus 'Twilight' (Syn. Eurybia x herveyi): Lavender-blue flowers with a yellow centre in late summer. Mildew-resistant foliage. An earlier flowering variety. Height to 1m.

Catananche caerulea (Cupid's dart): Masses of papery lavender blue flowers held on wiry stems all summer. Seed heads turn silver in late summer. Good dried flower. Up to 60cm. [Collect Only]

Catananche caerulea 'Major' (Cupid's dart 'Major'): Masses of papery blue flowers held on wiry stems all summer. Seed heads turn silver in late summer.

Nepeta racemosa 'Walker's Low' (Catmint 'Walker's Low'): Forms neat mounds of silvery green foliage, topped with masses of lavender blue flowers in early summer. Up to 60cm. Hardy.

Veronica austriaca 'Crater Lake Blue' (Speedwell 'Crater Lake Blue'): Vivid blue spikes above a mound of green foliage.To 30cm. Hardy.