Asphodeline lutea (Asphodel): Vertical spikes of sulphur yellow flowers in early to mid-summer. Hardy, but dislikes heavy soil in winter. To 1.2m

Baptisia 'Solar Flare' (Indigo weed 'Solar Flare'): New Baptisia with unusual golden yellow pea-like flowers which deepen in colour as they age producing a multicoloured effect. Hardy. Up to 90cm. [Collect Only]

Baptisia australis (Indigo weed): Spires of lipped indigo flowers over olive-green foliage. Flowering height 1.2m. [Collect Only]

Centaurea 'John Coutts' (Knapweed 'John Coutts'): Large almost fluffy soft pink flowers over green, slightly felty foliage with white undersides. To 40cm. Hardy.

Centaurea 'Silver Feather' PBR: A choice perennial with fluffy lilac-pink flowers over beautiful silver finely divided foliage. Evergreen. Full sun and good drainage. To 40cm. Hardy.

Centaurea montana (Perennial cornflower): Large blue flowers in early summer, repeated later in year if cut back. Very attractive to bees. To 50cm. Hardy

Centaurea montana 'Grandiflora' (Perennial cornflower 'Grandiflora'): Larger blue flowers than the species, with darker purple heart in early summer, cut back for repeat flowering. Very attractive to bees. To 50cm. Hardy

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]

Geranium macrorrhizum 'Bevan's Variety' (Cranesbill 'Bevan's Variety'): Superb ground cover Geranium especially for dry shade. Bright pink over a dense mound of aromatic foliage. Hardy. To 30cm.

Nepeta 'Six Hills Giant' (Catmint 'Six Hills Giant'): A vigorous sun lover which will soon make a generous clump. Spikes of tiny purple flowers over aromatic grey/green foliage.

Nepeta racemosa 'Walker's Low' (Catmint 'Walker's Low'): Forms neat mounds of silvery green foliage, topped with masses of lavender blue flowers in early summer. Up to 60cm. Hardy.

Nepeta x faasenii (Catmint): A compact variety of catmint with mounds of aromatic silvery green foliage and lavender blue flowers.Hardy. Up to 45cm.

Nepeta x faasenii 'Purrsian Blue': A compact variety of catmint with mounds of aromatic silvery green foliage and lavender blue flowers.Hardy. Up to 45cm.

Nepeta x faassenii 'Kit Cat' (Catmint 'Kit Cat'): A compact variety of catmint making a neat mound of aromatic green foliage and clusters of lavender blue flowers. Hardy. Up to 30cm.

Saxifraga x urbium (London Pride): Wiry stems topped with dainty pale pink flowers over ground evergreen rosettes of green leaves with creamy yellow markings.

Sedum spathulifolium 'Purpureum' (Purple stonecrop): Mat forming, fleshy purple rosettes with an attractive grey cast when young. Yellow flowers in summer.

Sisyrinchium striatum: Open fans of strappy iris-like leaves topped with lemon yellow flowers in summer. [Collect Only]

Tellima grandiflora 'Forest Frost' (Fringecups): Slender spikes of pinkish flowers late spring to mid-summer. Semi-evergreen reddish foliage. Great in shade. Height to 30cm. Hardy

Veronica austriaca 'Crater Lake Blue' (Speedwell 'Crater Lake Blue'): Vivid blue spikes above a mound of green foliage.To 30cm. Hardy.