24 KEY PLANTS
1 Phillyrea angustifolia Tough, evergreen shrub that needs plenty of light and resents winter wet. Responds well to being clipped. 3m. RHS H5†.
2 Dianthus carthusianorum Star-like flowers are held on stiff stems above tussocks of grass-like, evergreen foliage and vary in colour from pale pink through to reddish magenta. Prefers a slightly chalky, well-drained soil in full sun. 50cm. RHS H7. 3 Salvia azurea Willowy but tough salvia with an upright habit. Sky-blue flowers emerge in mid to late summer and persist until the first frosts. Can tolerate some shade but prefers full sun. Drought tolerant. 1.2m. RHS H5, USDA 5a-9b. 4 Bituminaria bituminosa Drought-tolerant perennial with delicate, lavender-blue pea-like flowers on wiry stems in spring. The green-grey, evergreen foliage has a strong and distinctive smell of bitumen. Full sun. 30cm. RHS H3-4. 5 Euphorbia rigida Early flowering perennial spurge with dramatic, glaucous, whorled stems of spiky leaves. Acid-green flowers take on reddish hues later in the season. Needs good drainage and full sun. 60cm. AGM*. RHS H6, USDA 7a-10b. 6 Cephalaria leucantha Pale-yellow, almost white, pincushion flowers on wiry stems with attractive, dissected, grey-green foliage. The whole effect is one of pleasing lightness. Prefers full sun on poor, well-drained soil. Will self-seed. 1.6m. RHS H4. 7 Stipa calamagrostis Semi-evergreen, mound-forming grass with feathery plumes of flowers in June that quickly turn an attractive biscuit brown and persist through winter. Will become floppy if grown on too rich a soil or in shade. 1.2m. AGM. RHS H4. 8 Centranthus ruber ‘Albus’ White form of the usually red or pink valerian. Upright stems produce soft heads of white flowers from late spring into early summer. Prefers dry, stony or chalky soils. Will self-seed vigorously. 1m. RHS H5. 9 Foeniculum vulgare Stately, if short-lived, perennial. Strong, self-supporting stems are topped with yellow umbels, much loved by pollinators. Will self-seed to the point of nuisance, but few dry gardens should be without it. 2m. RHS H4, USDA 4a-9b. 10 Euphorbia characias Iconic Mediterranean sub-shrub with felty, glaucous foliage and acid-green flowers in the early spring. The long-lasting inflorescences provide interest well into late summer. Very drought tolerant. Full sun. RHS H5.
11 Linaria vulgaris ‘Alba’ Masses of small, pure-white flowers with a yellow splotch at the mouth in midsummer. Best on poor soil in full sun. Will self-seed. RHS H4. 12 Lotus dorycnium Produces a mass of white pea-like flowers from May to July. Drought tolerant. Best on poor soil in full sun. 60cm. RHS H5. *Holds an Award of Garden Merit from the Royal Horticultural Society. †Hardiness ratings given where available.