Calamintha nepeta 'White Cloud': Spikes of small white flowers above mounds of minty scented green leaves. Loved by bees and butterflies. Hardy. Up to 30cm.

Campanula glomerata 'Alba' (White clustered bellflower): Tight clusters of white flowers on short stems above neat, mat-forming foliage. Height about 30cm. Hardy.

Centaurea montana 'Alba' (Perennial cornflower - white): Large white cornflower-like flowers over grey-green foliage. To 30cm. Hardy.

Geranium sanguineum 'Album' (Bloody cranesbill 'Album'): Pure white flowers over a mat of dark green leaves. Height to 20cm. Fully hardy.

Primula denticulata var. alba (Drumstick primula - white): Pure white balls of flowers on sturdy stems. To 25cm. Hardy

Sisyrinchium idahoense 'Album': White star-like flowers with a yellow centre, grass-like strappy foliage. Prefers a sunny spot with good drainage. Hardy. Up to 15cm.