Campanula persicifolia 'Chettle Charm' (Peach-leaved bellflower 'Chettle Charm'): Large white cups with tinged with violet blue at the petal edges. Very pretty summer flowering perennial. To 75cm.

Campanula persicifolia var. alba (Peach-leaved bellflower white flowered): Pure white large rounded cups on upright stems. Long flowering. Height to 70cm. Hardy.

Cenolophium denudatum (Seseli libanotis, Baltic parsley): Flat umbels of pretty white flowers in summer. Fine, filigree foliage. Great in borders, sun or part shade. Hardy. To 90cm

Centranthus ruber 'Albus' (White Valerian): White panicles of white flowers in mid-late summer. Very easy, self-seeds. Perennial and hardy. To 60cm.

Tradescantia (Andersoniana Group) 'Osprey' (Spider lily 'Osprey'): Three-petalled white flowers with a fluffy blue centre above strappy foliage. Great as a ground clump former in sun or part shade.