Asphodeline lutea (Asphodel):
Vertical spikes of sulphur yellow flowers in early to mid-summer. Hardy, but dislikes heavy soil in winter. To 1.2m
Euphorbia characias subsp. wulfenii (Mediterranean spurge):
Evergreen perennial with blue-green leaves and vibrant lime-green flowers in early summer. Prefers full sun. Hardy to about -10C, but not for long periods. Up to 1.2m.
[Collect Only]
Gaura lindheimeri 'The Bride':
Beautiful airy stems of white flowers in mid to late summer. Best in full sun, in well drained soil and a sheltered spot. Stems up to 1m.
Salvia 'Hot Lips' (Sage 'Hot Lips'):
Bicolour flowers in white and lipstick red and delicious scented foliage. Half-hardy, copes with -5C in a sheltered spot. To 1m.