Geranium wlassovianum: Warm purple flowers over attractive velvety foliage. Excellent autumn foliage colour.

Lathyrus vernus (Spring pea): Two-tone purple and pink pea-like flowers in early spring. Thrives in shade, even quite dry shade. To 30cm. Hardy.

Liriope 'Big Blue' (Blue turf lily 'Big Blue'): Spikes of vibrant purple flowers in autumn, larger than the usual form, evergreen strappy foliage. Good for dry shade. Hardy. Up to 50cm

Liriope muscari 'Royal Purple' (Blue turf lily 'Royal Purple'): Spikes of deep purple flowers in autumn above dark-green evergreen strappy foliage. Can tolerate dry shade. Hardy. Up to 50cm.