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.

Geranium palmatum: Bright pink flowers held on wiry stems above rosettes of evergreen foliage. To 60cm. Frost hardy.

Penstemon 'Garnet' (Syn. Penstemon 'Andenken an Friedrich Hahn'): Wine-red tubular flowers with white throat markings and narrow leaves. Semi-evergreen in milder areas. Protect from hard frosts.

Penstemon 'Pensham Plum Jerkum': Plum-purple tubular flowers with white throat markings. Semi-evergreen in milder areas. Protect from hard frosts. To 70cm.

Penstemon 'Schoenholzeri': Brilliant scarlet tubular flowers, slender leaves.

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.

Salvia x jamensis 'Nachtvlinder' (Sage 'Nachtvlinder'): Regal purple flowers on upright stems throughout late summer into autumn.

Verbena hastata 'Alba' (American blue vervain 'Alba'): Tall, branched stems like a candelabra with spikes of small white flowers loved by bees. Needs a sheltered spot & full sun. Up to 1.2m.

Verbena hastata 'Rosea' (American blue vervain 'Rosea'): Tall, branched stems like a candelabra with spikes of small pink flowers loved by bees. Needs a sheltered spot in full sun. Up to 1.2m.