Campanula takesimana 'Elizabeth' (Korean Bellflower): Upright stems with dark pink drooping large bells. Can be vigorous on good soil. May need some support. Bee-friendly. Hardy. Up to 70cm.

Centaurea dealbata (Persian cornflower): Large, showy pink flowers over deeply divided foliage. Makes a good-sized clump in a couple of years. To 60cm. 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

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

Centranthus ruber var. coccineus (Valerian dark red): Panicles of dark-red flowers in mid-summer, loved especially by butterflies. Classic cottage garden plant. Hardy. Up to 50cm. [Collect Only]

Euphorbia amygdaloides var. robbiae (Mrs Robb's bonnet): Great plant for difficult dry, shady areas. Evergreen dark-green leaves and vibrant lime-green flowers in spring. Suckers and can spread.

Geranium himalayense 'Derrick Cook' (Cranesbill 'Derrick Cook'): Large white flowers with delicate purple veining above a clump of bright green leaves. Foliage turns red in autumn. To 35cm. Hardy. [Collect Only]

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 grandiflora 'Summer Magic' (PBR) (Catmint 'Summer Magic'): A more compact, upright growing variety of Catmint with aromatic grey foliage and spikes of lavender blue flowers. Hardy. Up to 35cm. [Collect Only]

Persicaria bistorta 'Hohe Tatra' (Bistort 'Hohe Tatra'): Upright pink spikes from May to July. Flowers slightly smaller and later than 'Superba'. Hardy. Height to 45cm. [Collect Only]

Persicaria bistorta 'Superba' (Bistort 'Superba'. Syn. Polygonum bistorta 'Superbum'): Upright fluffy pink spikes make a bold show in early summer. Great for filling larger spaces. Hardy. Up to 60cm.

Physalis alkekengi var. franchetii (Chinese Lantern): Hardy perennial, grown for its glowing orange lantern-like seed cases in autumn.

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.

Tradescantia (Andersoniana Group) 'Red Grape' (Spider lily 'Red Grape'): Three-petalled large, reddish-pink flowers above strappy green foliage. Great as a ground clump former in sun or part shade. Hardy. Up to 50cm.