Achillea 'Fanal' (Yarrow)

A clump-forming, deciduous perennial with finely-divided, grey-green leaves and, in summer, erect, stems bearing dense, flattened corymbs of tiny, red flowers with yellow eyes. Height 75cm (2.5ft), Spread 60cm (2ft).

Achillea 'Pink Grapefruit' (Yarrow)

A clump-forming, deciduous to semi-evergreen perennial with dark grey-green leaves and, from summer into autumn, erect stems bearing dense, flattened clusters of tiny, rose-pink flowers fading to pale pink with age.

Achillea 'Saucy Seduction' (Yarrow)

An upright, clump-forming, deciduous to semi-evergreen perennial with aromatic, grey-green leaves & erect stems bearing dense, flattened clusters of magenta to deep rose-pink flowers in summer. Height & Spread 60cm (2ft).

Achillea 'Terracotta' (Yarrow)

A semi-evergreen perennial with rich burnt orange to golden yellow flat blooms above neat mounds of aromatic, greyish-green, ferny foliage. Height 1m (3ft), Spread 50cm (1.5ft).

Achillea filipendulina 'Cloth of Gold' (Yarrow)

A clump-forming, herbaceous perennial with light-green, finely divided leaves. From late summer to early autumn, it bears flat umbels of golden-yellow flowers. Height 1.5m (5ft), Spread 50cm (1.5ft).

Achillea millefolium 'Milly Rock Terracotta' (Yarrow)

A compact, mound-forming, deciduous to semi-evergreen perennial with finely-divided, dark grey-green leaves and erect stems bearing dense, flattened clusters of tiny, vibrant, orange-yellow flowers from summer into autumn.

Aconitum napellus subsp. vulgare 'Albidum'

An upright, tuberous, deciduous perennial with rounded, dark green leaves divided into five to seven, slender, toothed lobes and dense racemes of hooded, white flowers in summer. Height 1.5m (5ft), Spread 50cm (1.5ft).

Agapanthus 'Double Diamond' (African Lily)

A compact, clump-forming, evergreen to semi-evergreen perennial with strap-shaped, mid-green leaves, and sturdy, erect stems bearing rounded umbels of double, bell- to funnel-shaped, white flowers in summer.

Agapanthus 'Ever White' (African Lily)

A semi-dwarf, compact herbaceous perennial with stap-shaped, green leaves producing multiple, upright stems with clusters of pure white flowers throughout the summer. Height & Spread 50cm (1.5ft).

Agapanthus 'Fireworks' (African Lily)

A clump-forming, half-hardy, evergreen perennial with strap-shaped, dark green leaves, and, in summer, sturdy, erect stems bearing rounded umbels of trumpet-shaped, white flowers, purple at the base.

Agapanthus 'Golden Drop' (African Lily)

A deciduous, clump-forming perennial with slender green leaves banded with yellow. Clusters of lilac-blue flowers on tall stems in mid to late summer. Height & Spread 50cm (1.5ft).

Agapanthus 'Jacaranda' (African Lily)

A clump-forming, half-hardy, perennial with strap-shaped, dark green leaves, and, in early to midsummer, erect stems bearing umbels of trumpet-shaped, violet-blue flowers with a dark stripe in the centre of each petal.

Agapanthus 'Northern Star' (African Lily)

A clump-forming, deciduous perennial with strap-shaped, dark green leaves, and, in early to mid-summer erect stems bearing rounded umbels of violet-blue flowers with a dark purple stripe down the centre of each petal.

Agapanthus 'Poppin' Purple' (African Lily)

A clump-forming, half-hardy, evergreen perennial bearing strap-shaped, dark green leaves and sturdy, erect stems bearing rounded umbels of dark purple buds opening to trumpet-shaped, purple flowers throughout summer.

Agapanthus 'Royal Velvet' (African Lily)

A clump-forming, borderline hardy, deciduous perennial with broad, strap-shaped, dark green leaves, and sturdy, erect stems bearing rounded, open umbels of trumpet-shaped, deep purple flowers in summer.

Agapanthus 'Silver Baby' (African Lily)

A compact, clump-forming, half-hardy, evergreen perennial with broad, strap-shaped, dark green leaves, and sturdy, erect stems bearing rounded umbels of trumpet-shaped, blue-flushed, white flowers in summer.

Agapanthus 'Snow Crystal' (African Lily)

A clump-forming, half-hardy, evergreen perennial with strap-shaped, dark green leaves, and sturdy, erect stems bearing rounded umbels of funnel-shaped, white flowers from midsummer to early autumn.

Agapanthus 'Streamline' (African Lily)

A small, semi-evergeen perennial with clumps of strap-like, mid-green leaves and open, mid-blue flowerheads borne on strong stems in summer to early autumn. Height & Spread 50cm (1.5ft).

Agapanthus 'Tinkerbell' (African Lily)

A compact, semi-evergreen perennial forming a clump of strap-shaped, dark grey-green leaves with creamy-white margins and sturdy, upright stems bearing large, spherical heads of tubular blue flowers in late summer.

Agapanthus 'Twister' (African Lily)

A compact, clump-forming, half-hardy, deciduous perennial with broad, strap-shaped, dark green leaves, and, in summer, sturdy, erect stems bearing rounded umbels of trumpet-shaped, white flowers, purple-blue at the base.

Agapanthus Headbourne Hybrids (African Lily)

A hardy, upright perennial with rounded heads of deep blue, pale blue or white trumpet-shaped flowers that rise above green strappy leaves in late summer. Height 1.2m (4ft), Spread 60cm (2ft).

Agapanthus campanulatus var. albidus (African Lily)

An upright perennial with deciduous, narrow, strap-like, grey-green leaves, and tall rounded clusters of white, bell-shaped flowers in summer. Height 60cm (2ft), Spread 50cm (1.5ft).

Agapanthus inapertus 'Kilmurry Blue' (African Lily)

A clump-forming, deciduous perennial with erect, strap-shaped, mid-green leaves and sturdy, upright stems bearing rounded umbels of violet-blue flowers with a purple stripe in late summer and early autumn.

Agapanthus umbellatus 'Albus' (Lily Of The Nile)

A clump-forming, herbaceous perennial with glossy, dark green, strap-shaped leaves and large umbels of very large, funnel-shaped white flowers in mid and late summer.

Agastache 'Blackadder' (Giant Hyssop)

An upright, clump-forming, herbaceous perennial with aromatic, dark grey-green leaves and whorled spikes dark purple buds opening to tubular, two-lipped, fragrant, violet flowers from summer to early autumn.

Agastache rugosa 'Little Adder' (Korean Mint)

A compact, mound-forming, deciduous perennial with upright stems bearing aromatic, mid- to dark green leaves and erect spikes of tubular, lavender flowers from midsummer into autumn. Height & Spread 50cm (1.5ft).

Alcea rosea 'Chater's Double Scarlet' (Hollyhock)

A vigorous, upright biennial or short-lived perennial with lobed, rounded, rough, mid- to dark green leaves and large, double, scarlet-red flowers in summer. Height 2m (6ft), Spread 60cm (2ft).

Alchemilla mollis (Lady's Mantle)

Ground-covering perennial. Tiny, bright greenish-yellow flowers in mid-summer that may be dried. Height & Spread 50cm (1.5ft). Plant in full or partial sun.

Allium senescens 'Little Sapphire' (German Garlic)

A vigorous, clump-forming, bulbous perennial with strap-shaped, mid-green leaves and erect stems bearing dense umbels of cup-shaped, purple flowers in summer. Height 30cm (1ft), Spread 20cm (8in).

Alstroemeria 'Inticancha Sunset' (Peruvian Lily)

A compact, bushy, clump-forming perennial with upright stems bearing dark green leaves &, from summer into autumn, open clusters of creamy yellow, funnel-shaped flowers with a rich pink splash. Height & Spread 30cm (1ft).

Amsonia 'Blue Ice'

A compact, mound-forming, deciduous perennial with upright stems bearing dark green leaves turning yellow-orange in autumn and rounded, open panicles of star-shaped, lavender-blue flowers in late spring and early summer.

Anemone 'Fantasy Jasmine' (Japanese Anemone)

A compact, upright, deciduous, woody-based perennial with rounded to oval leaves and slender, wiry stems bearing umbels of saucer-shaped, deep-pink flowers from late summer into autumn. Height & Spread 50cm (1.5ft).

Anemone hupehensis 'Praecox' (Japanese Anemone)

An erect, clump-forming, herbaceous perennial with deeply divided, dark green basal leaves and, from late summer into autumn, upright, wiry stems bearing single, deep pink flowers with yellow centres.

Anemone x hybrida 'Honorine Jobert' (Japanese Anemone)

One of the most beautiful plants for late summer and early autumn, this makes clumps of large, dark, divided, vine-line leaves and pure white flowers with contrasting yellow stamens. Height 1.5m (5ft), Spread 1m (3ft).

Anemone x hybrida 'Queen Charlotte' (Japanese Anemone)

A pretty perennial with divided leaves and large, pink, semi-double flowers in summer. Height 1.5m (5ft), Spread 1m (3ft).

Angelica gigas (Korean Angelica)

A large short lived herbacous perennial with attractive divided foliage. In late summer to early autumn, it bears large rounded umbels of purple flowers on red-flushed, branching stems. Height & Spread 1.2m (4ft).

Anthemis tinctoria 'E.C. Buxton' (Dyer's Chamomile)

A clump-forming, evergreen perennial with finely-cut, fern-like green leaves and masses of light yellow daisies on single, slim stems from mid-summer until the first frosts. Height & Spread 1m (3ft).

Aquilegia 'Crimson Star' (Columbine)

An upright, herbaceous perennial with deeply lobed, mid-green leaves and stems bearing pendant flowers with red sepals and creamy white petals from late spring to midsummer. Height 60cm (2ft), Spread 30cm (1ft).

Aquilegia 'Red Star' (Columbine)

A short-lived, clump-forming, herbaceous perennial with mid-green leaves and slender, upright stems bearing pendant flowers with red outer sepals and white inner petals in spring and early summer.

Aquilegia vulgaris var. stellata 'Ruby Port' (Columbine)

A mound-forming, herbaceous perennial with finely-divided, light green leaves and upright stems bearing double, nodding, deep red to maroon flowers in late spring and early summer. Height 1m (3ft), Spread 50cm (1.5ft).

Artemisia ludoviciana 'Silver Queen' (Western Mugwort)

A clump-forming, herbaceous perennial with lance-shaped, downy, greyish-white leaves and, occasionally, plumes of small, insignificant brownish-yellow flowers in late summer to early autumn. Height & Spread 1m (3ft).

Aster novi-belgii 'Bahamas' (Michaelmas Daisy)

A compact, bushy perennial with lance-shaped, mid-green leaves & double, incurved, deep blue, light blue, rose, scarlet or white flower heads in summer until autumn. Mildew resistant. Height 60cm (2ft), Spread 30cm (1ft).

Aster novi-belgii 'Barbados' (Michaelmas Daisy)

A compact, mound-forming, rhizomatous perennial with branching stems, lance-shaped, mid-green leaves and clusters of pale purple flowers with yellow centres from late summer to mid-autumn. Height & Spread 50cm (1.5ft).

Aster novi-belgii 'Jenny' (Michaelmas Daisy)

A compact, mound-forming, deciduous perennial with narrowly lance-shaped, dark green leaves and clusters of semi-double, magenta flowers from late summer into autumn. Height & Spread 50cm (1.5ft).

Aster novi-belgii 'Purple Dome' (Michelmas Daisy)

A domed or mound-forming, deciduous perennial with narrowly lance-shaped, mid-green leaves and, in autumn, clusters of semi-double, purple flowers with yellow centres. Height & Spread 60cm (2ft).

Aster novi-belgii 'Samoa' (Michaelmas Daisy)

An upright, bushy perennial with lance-shaped, dark green leaves and double, incurved, purple-pink flower heads in summer until autumn. Height 60cm (2ft), Spread 30cm (1ft).

Aster novi-belgii 'Snow Cushion' (Michaelmas Daisy)

A compact, mound-forming perennial with narrow, green leaves and clusters of white daisy-like flowers with yellow centres in late summer and autumn. Height & Spread 50cm (1.5ft).

Aster novi-belgii 'Tonga' (Michaelmas Daisy)

A compact, bushy, dwarf, clump-forming, perennial with branching stems, lance-shaped, mid-green leaves and clusters of double, bright purple flowers with yellow centres from late summer to mid-autumn.

Aster x frikartii 'Monch' (Frikart's Aster)

An upright, bushy herbaceous perennial with ovate, rough, dark green leaves and loose clusters of yellow-centred, lavender-blue flowers from late summer to early autumn. Height 1m (3ft), Spread 50cm (1.5ft).

Astilbe japonica 'Europa'

A perennial with feathery fern-like foliage, which unfurls in spring, followed in late spring and summer with plumes of soft pink flowers. Height & Spread 1m (3ft).

Astilbe x arendsii 'Erika'

A tall, spreading perennial with finely divided, dark green leaves that open burgundy-red in spring and panicles of pink flowers in summer. Height 1m (3ft), Spread 60cm (2ft).

Astilbe x arendsii 'Fanal'

A perennial with with deeply-divided, deep green leaves and feathery dark-pink, crimson flowers. Height & Spread 50cm (1.5ft).

Astrantia major 'Venice' (Masterwort)

An upright, clump-forming perennial with deeply divided, palmate, toothed, mid-green leaves and, in summer, erect stems bearing dark ruby-red flowers surrounded by dark reddish-purple bracts.

Astrantia major subsp. involucrata 'Shaggy' (Masterwort)

A herbaceous perennial, with divided leaves and branching stems bearing greenish-white flowers surrounded by narrow, green-tipped white or pinkish bracts. Height 1m (3ft), Spread 50cm (1.5ft).

Bergenia 'Eroica' (Elephant's Ears)

A clump-forming, evergreen perennial bearing obovate to heart-shaped, wavy, glossy, burgundy-flushed, dark green leaves turning burgundy in winter and clusters of bright rose-pink flowers on red stems in mid-spring.

Bergenia 'Rose Crystal' (Elephant's Ears)

A clump-forming, evergreen perennial bearing oval, leathery, mid-green leaves and upright stems bearing dense clusters of open bell-shaped, pink flowers in mid-spring. Height 30cm (1ft), Spread 60cm (2ft).

Brunnera macrophylla 'Sea Heart' (Siberian Bugloss)

A mound-forming, rhizomatous perennial, bearing large, heart-shaped, silver-marked, dark green leaves and, in spring, airy panicles of small, lightly fragrant, blue flowers fading pink or lavender with age.

Campanula carpatica 'White Clips' (Tussock Bellflower)

A small, spreading, mound-forming, herbaceous perennial with fresh-green, heart-shaped leaves. From early summer to early autumn, it is covered with white, cup-shaped flowers. Height 30cm (1ft), Spread 50cm (1.5ft).

Campanula persicifolia (Peach-Leaved Bellflower)

An upright perennial with evergreen, narrow, bright green basal leaves and, in summer, short, terminal racemes of slightly pendent, cup-shaped flowers varying from white to lilac-blue. Height 1m (3ft), Spread 30cm (1ft).

Canna 'Kreta'

An erect, rhizomatous perennial bearing large, pointed, banana-like, bright green leaves and sturdy stems bearing racemes of rose-red flowers from midsummer into autumn. Height 1.5m (5ft), Spread 90cm (3ft).

Canna 'Tropicanna Black'

An erect, rhizomatous perennial with large, banana-like, dark maroon leaves and strong, erect stems bearing racemes of bright orange-red flowers from summer to early autumn. Height 2m (6ft), Spread 75cm (2.5ft).

Canna 'Tropicanna'

An upright, rhizomatous perennial with large, banana-like, dark green, yellow and red-striped leaves and strong, erect stems bearing racemes of yellow-orange flowers from midsummer into early autumn.

Canna x generalis 'Cannova Bronze Scarlet'

An erect, rhizomatous perennial bearing large, pointed, banana-like, dark bronze-green leaves and sturdy stems bearing racemes of scarlet flowers from midsummer into autumn. Height 75cm (2.5ft), Spread 60cm (2ft).

Canna x generalis 'Cannova Mango'

An erect, rhizomatous perennial bearing large, pointed, banana-like, dark green leaves and sturdy stems bearing racemes of salmon-pink flowers from midsummer into autumn. Height 1.2m (4ft), Spread 60cm (2ft).

Canna x generalis 'Cannova Red Shades'

An erect, rhizomatous perennial bearing large, pointed, banana-like, dark green leaves and sturdy stems bearing racemes of red flowers from midsummer into autumn. Height 1.2m (4ft), Spread 60cm (2ft).

Canna x generalis 'Cannova Rose'

An erect, rhizomatous perennial bearing large, pointed, banana-like, dark green leaves and sturdy stems bearing racemes of rose-pink flowers from midsummer into autumn. Height 1.2m (4ft), Spread 60cm (2ft).

Canna x generalis 'Tropicana Gold'

An upright perennial with large, ovate, green and gold striped leaves, and bright yellow/orange flowers in summer. Height 2m (6ft), Spread 50cm (1.5ft).

Centaurea montana 'Alba' (White Perennial Cornflower))

A rhizomatous, mat-forming perennial with ovate to lance-shaped, sometimes lobed and toothed, mid-green leaves and white flowerheads from late spring to midsummer. Height 50cm (1.5ft), Spread 75cm (2.5ft).

Centaurea montana (Perennial Cornflower)

A low-growing herbaceous perennial forming a clump of green, lance-shaped leaves and, in summer, electric blue flowers with a red centre. Height 60cm (2ft), Spread 50cm (1.5ft).

Centranthus ruber 'Alba Pura' (Valerian)

An upright, semi-evergreen perennial, sometimes grown as a biennial, with grey-green leaves & dense cymes of small, fragrant, funnel-shaped, white flowers from late spring into summer. Height 1m (3ft), Spread 50cm (1.5ft).

Ceratostigma plumbaginoides (Leadwort)

A mat-forming, spreading, herbaceous perennial with oval leaves which turn red or purple in autumn and bright blue flowers in late summer. Height & Spread 50cm (1.5ft).

Ceratostigma willmottianum 'Forest Blue'

A bushy, spreading, deciduous shrub with lance-shaped, dark green leaves turning red in autumn and clusters of vivid cobalt-blue flowers from late summer to early autumn. Height 1m (3ft), Spread 1.5m (5ft).

Cirsium rivulare 'Atropurpureum' (Plume Thistle)

A herbaceous perennial forming a clump of leafy stems with round, red-purple flower heads in summer. Height 1.5m (5ft), Spread 50cm (1.5ft).

Cirsium rivulare 'Trevor's Blue Wonder' (Plume Thistle)

An upright, clump-forming, herbaceous perennial with spiny, grey-green leaves, softly hairy beneath, and erect, purple-flushed stems bearing thistle-like, magenta flower heads in mid- to late summer.

Convallaria majalis (Lily Of The Valley)

A perennial with elliptic to narrowly ovate leaves and arching racemes of small, highly fragrant, bell-shaped flowers followed by red berries. Height & Spread 50cm (1.5ft).

Cosmos 'Chocamocha'

A dwarf, clump forming, herbaceous perennial with fine, green foliage and deep-maroon, velvet flowers that smell of chocolate. Height & Spread 30cm (1ft).

Crocosmia 'Hellfire' (Montbretia)

A robust perennial with pleated mid-green leaves and arching stems of bold red flowers in summer. Height 1.5m (5ft), Spread 1m (3ft).

Crocosmia 'Lucifer' (Montbretia)

A robust, spreading perennial with pleated mid-green leaves and arching stems of bold tomato-red flowers in summer. Height 1.5m (5ft), Spread 1m (3ft).

Crocosmia x crocosmiiflora 'George Davison' (Montbretia)

A clump-forming, deciduous perennial with erect, sword-shaped, dark green leaves and branched stems bearing spikes of yellow-orange flowers in summer. Height 1m (3ft), Spread 10cm (4in).

Crocosmia x crocosmiiflora 'Honey Angels' (Montbretia)

An upright perennial with mid-green, strap-shaped leaves and sprays of yellow, funnel-shaped flowers from mid-summer to early autumn. Height 60cm (2ft), Spread 30cm (1ft).

Crocosmia x crocosmiiflora 'Jackanapes' (Montbretia)

A clump-forming, cormous perennial with upright, sword-shaped, mid- to dark green leaves and, from midsummer to early autumn, arching bearing racemes of yellow-orange flowers, deep orange-red on the reverse.

Cynara scolymus 'Green Globe' (Artichoke)

A deciduous, thistle-like plant with arching silver leaves producing an edible globe vegetable just before flowering. This variety produces large green heads. Height 1.5m (5ft), Spread 50cm (1.5ft).

Dahlia 'Arabian Night'

An upright, bushy, clump-forming, tuberous perennial with pinnate, toothed dark green leaves from summer into autumn, strong, upright stems bearing double, dark red flowers with incurved petals.

Dahlia 'Bishop of Auckland'

A bushy, clump-forming, tuberous perennial with toothed, pinnate, purple- to black-flushed, dark green leaves and, from midsummer to early autumn, single, red flowers with orange-yellow centres.

Dahlia 'Bishop of Dover'

An upright, bushy, tuberous perennial with toothed, pinnate, purple-flushed, dark green leaves and upright, dark purple stems bearing single, violet-flushed, white flowers from midsummer into autumn.

Dahlia 'Bishop of Leicester'

A bushy, clump-forming, tuberous perennial with toothed, purple- to black-flushed, dark green leaves and, from midsummer to early autumn, pale lavender flowers with darker lavender bands down the centre of each petal.

Dahlia 'Bishop of Llandaff'

A deciduous perennial, with dark-red foliage and semi-double brilliant red flowers. Height 1m (3ft), Spread 50cm (1.5ft).

Dahlia 'Bishop of York'

A bushy, clump-forming, tuberous perennial with toothed, pinnate, purple to black-flushed, dark green leaves and single to semi-double, orange-flushed, yellow flowers from midsummer to early autumn.

Dahlia 'Black Jack'

An upright, bushy, tuberous perennial with toothed, pinnate, bronze- to purple-flushed dark green leaves and sturdy, upright stems bearing double, maroon to dark red flowers from summer into autumn.

Dahlia 'Black Narcissus' (Cactus Dahlia)

A bushy, clump-forming, tuberous perennial with toothed, pinnate, dark green leaves and, in summer and autumn, upright stems bearing double, black-flushed, dark red flowers with narrow, pointed petals.

Dahlia 'Chat Noir'

A tuberous perennial with divided green foliage, and rich deep red flowers on tall stems from summer until late autumn. Height 1.2m (4ft), Spread 50cm (1.5ft).

Dahlia 'Crazy Love'

An upright, bushy, clump-forming, tuberous perennial with dark green leaves and, from midsummer to early autumn, dark purple stems bearing double, white flowers with yellow-green centres and pale lilac-pink petal tips.

Dahlia 'David Howard'

A miniature-flowered decorative Dahlia with bronze-tinged, dark green, divided foliage and in summer and autumn it bears double bronze-orange flowers. Height & Spread 60cm (2ft).

Dahlia 'Fascination'

A tuberous perennial with purple-flushed foliage. From mid-summer to early autumn, it bears semi-double, pink flowers on dark, upright stems. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Dahlia 'Happy Days Red'

A compact, upright, bushy, clump-forming perennial with purple- or bronze-flushed, dark green leaves and strong, upright stems bearing single, red to orange-red flowers from summer into autumn. Height & Spread 50cm (1.5ft)

Dahlia 'Happy Days Rose'

A compact, upright, bushy, clump-forming, tuberous perennial with purple- or bronze-flushed, dark green leaves and strong, upright stems bearing single, magenta flowers from summer into autumn. Height & Spread 50cm (1.5ft)

Dahlia 'Honka Black'

An upright, bushy, clump-forming, perennial with green leaves and, from midsummer into autumn, upright stems bearing single, lightly fragrant, star-shaped, dark maroon flowers with rolled petals and golden-yellow centres.

Dahlia 'Honka'

An upright, bushy, clump-forming, tuberous perennial with green leaves &, in summer & autumn, upright stems bearing single, lightly fragrant, star-like, yellow flowers with rolled petals & bright orange or yellow centres.

Dahlia 'Karma Choc'

A bushy, clump-forming, tuberous perennial with toothed, pinnate, purple- to black-flushed, dark green leaves and, in summer and autumn, dark stems bearing double, dark red to maroon flowers.

Dahlia 'Nuit d'Ete'

A bushy, clump-forming, tuberous perennial with toothed, pinnate, dark green leaves and, in summer and autumn, upright stems bearing double, dark maroon flowers with narrow, pointed petals.

Dahlia 'Purple Haze'

A bushy, clump-forming, tuberous perennial with toothed, pinnate, dark green leaves and upright, red-flushed stems bearing double, reddish-purple to magenta flowers in summer and autumn. Height 1m (3ft), Spread 60cm (2ft).

Dahlia 'Thomas A. Edison'

An upright, bushy, clump-forming, tuberous perennial with toothed, pinnate, dark green leaves and, from summer into autumn, double, reddish-purple flowers with paler outer petals. Height 1m (3ft), Spread 50cm (1.5ft).

Delphinium 'Atlantis'

A clump-forming, deciduous, medium-sized perennial with deeply segmented leaves. In early summer it has violet blue flowers with white eyes. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Delphinium 'Christel'

An upright, clump-forming, herbaceous perennial with dark green leaves and tall spikes of double, dark purple-blue flowers in summer. Height 1.5m (5ft), Spread 60cm (2ft).

Delphinium 'Dark Blue White Bee'

A semi-dwarf, clump-forming perennial with lobed, mid-green leaves and tall spikes of deep purple flowers with white centres in summer. Height 1m (3ft), Spread 60cm (2ft).

Delphinium 'Delgenius Shelby'

A vigorous, upright, compact, clump-forming, deciduous perennial with deeply lobed, dark green leaves and erect racemes of semi-double, pale blue flowers in summer. Height 60cm (2ft), Spread 50cm (1.5ft).

Delphinium 'Guardian Blue'

A low, clump-forming, herbaceous perennial with deeply lobed, mid-green leaves and erect spikes of blue flowers in summer. Height 1m (3ft), Spread 60cm (2ft).

Delphinium 'Guardian Lavender'

A low, clump-forming, herbaceous perennial with deeply lobed, mid-green leaves and erect spikes of lavender flowers in summer. Height 1m (3ft), Spread 60cm (2ft).

Delphinium 'Guardian White'

A low, clump-forming, herbaceous perennial with deeply lobed, mid-green leaves and erect spikes of white flowers in summer. Height 1m (3ft), Spread 60cm (2ft).

Delphinium 'Light Blue with White Bee'

An upright, clump-forming perennial with palmately lobed, dark green leaves and, in summer, dense, erect, branching racemes of bowl-shaped, semi-double, pale blue flowers with white centres.

Delphinium 'Piccolo'

An upright, clump-forming, vigorous, herbaceous perennial with palmately lobed, dark green leaves and erect, racemes of bright blue flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

Delphinium 'Volkerfrieden'

A tall herbaceous perennial with deeply segmented green leaves. It has two blooming periods producing compact spires of bright blue panicles in early and late summer. Height 1m (3ft), Spread 60cm (2ft).

Dianella caerulea 'Cassa Blue' (Blue Flax Lily)

A tender, tufted, rhizomatous, evergreen perennial with stiff, upright, blue-green leaves and, in summer, panicles of pendent, star-shaped, blue flowers followed by spherical, glossy, purple fruit.

Dicentra formosa 'Luxuriant'

A spreading perennial with lobed, mid- to dark green leaves and racemes of heart-shaped, red flowers in mid-spring to summer. Height & Spread 30cm (1ft).

Dicentra spectabilis 'Alba' (White Bleeding Heart)

A clump-forming, herbaceous perennial with deeply-divided, light green leaves and arching racemes of nodding, heart-shaped, white flowers in late spring and early summer. Height & Spread 1m (3ft).

Dicentra spectabilis (Bleeding Heart)

A clump-forming perennial with divided, bright green leaves and arching stems bearing racemes of rose-pink and white flowers in late spring and early summer. Height 1.2m (4ft), Spread 50cm (1.5ft).

Digitalis 'Pink Panther' (Foxglove)

A compact, rosette-forming, hairy biennial or perennial with ovate to lance-shaped, toothed, dark green leaves and, in summer, tall, upright spikes of rose-pink flowers with spotted throats.

Digitalis parviflora 'Milk Chocolate' (Foxglove)

A biennial with glossy, dark green basal leaves and tall, upright spikes of red-brown flowers with purple veining in summer. Height 60cm (2ft), Spread 50cm (1.5ft).

Digitalis purpurea 'Camelot Cream' (Foxglove)

A rosette-forming, hairy, biennial or perennial with toothed, dark green leaves and, in summer, tall, upright spikes of cream flowers with purple-speckled throats. This cultivar will bloom in the first and second year.

Digitalis purpurea 'Camelot Lavender' (Foxglove)

A rosette-forming, hairy biennial or deciduous to semi-evergreen perennial with toothed, dark green leaves and, from late spring into summer, upright spikes of lavender flowers with maroon-spotted throats.

Digitalis purpurea 'Virtuoso Rose Compact' (Foxglove)

A compact biennial or short-lived perennial with toothed green leaves. Tall spikes bear large, tubular to bell-shaped rose pink flowers with heavily spotted throats, from mid to late summer. Height & Spread 50cm (1.5ft).

Digitalis purpurea 'Virtuoso White' (Foxglove)

A biennial or short-lived perennial with toothed green leaves. Tall spikes bear large, tubular to bell-shaped creamy white flowers with purple spotted throats, from mid to late summer. Height 1m (3ft), Spread 50cm (1.5ft).

Digitalis x valinii 'Foxlight Plum Gold' (Foxglove)

A rosette-forming, semi-evergreen perennial with erect stems bearing dark green leaves and, from late spring to late summer, upright spikes of reddish-pink flowers with golden-yellow, spotted throats.

Digitalis x valinii 'Foxlight Rose Ivory' (Foxglove)

A rosette-forming, semi-evergreen perennial with erect stems bearing dark green leaves and, from late spring to late summer, upright spikes of rose-pink flowers with light orange, spotted throats.

Echinacea purpurea 'Avalanche' (Coneflower)

A compact, upright, clump-forming, herbaceous perennial with rough-hairy, dark green leaves and, from midsummer to early autumn, flowers with white petals surrounding a yellow-green central cone.

Echinacea purpurea 'Green Twister' (Coneflower)

An upright, clump-forming, herbaceous perennial with dark green leaves and, throughout summer, dark stems bearing green-tipped, bright pink flowers with orange-brown central cones. Height 1m (3ft), Spread 50cm (1.5ft).

Echinacea purpurea 'Magnus' (Coneflower)

An upright, clump-forming perennial with toothed, dark green leaves and large, purple-pink petals surrounding a dark orange cone in midsummer to mid-autumn. Height 1m (3ft), Spread 60cm (2ft).

Echinacea purpurea 'White Swan' (Coneflower)

An erect, herbaceous perennial with ovate, toothed, hairy basal leaves, ovate to lance-shaped, toothed stem leaves and solitary, white daisy-like flower-heads with yellow central disks.

Echinops ritro 'Veitch's Blue' (Small Globe Thistle)

A clump-forming perennial, with deeply lobed, dark green, thistle-like foliage, and globular, steel-blue flowerheads on silver-grey, branched, leafy stems. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Echinops ritro (Small Globe Thistle)

A robust perennial, with divided, prickly dark green leaves whiter underneath, and round, violet-blue flowerheads on silver-grey, branched, leafy stems. Height 1m (3ft), Spread 50cm (1.5ft).

Echium pininana (Giant Viper's Bugloss)

A biennial producing a low rosette of silvery-green, lance-shaped leaves in its first year. In its second year, it bears large spires of blue flowers on stout stems. Height 3m (10ft), Spread 1m (3ft).

Erigeron 'Azure Fairy' (Fleabane)

A clump-forming perennial with lance-shaped leaves and abundant numbers of small, semi-double, yellow-centred, lavendar-blue flowers in summer. Height & Spread 50cm (1.5ft).

Erodium manescavii (Showy Heron's Bill)

A mat-forming perennial with dark grey-green, dissected leaves and deep pink storksbill flowers over a long season from summer. Height & Spread 60cm (2ft).

Eryngium planum 'Blauer Zwerg' (Sea Holly)

A perennial forming clumps of branched stems, and cone-like, lilac-blue flowerheads with spiny bracts in late summer. Height & Spread 50cm (1.5ft).

Eryngium planum 'Blue Hobbit' (Sea Holly)

A herbaceous perennial with spiny edged leaves and masses of spiky, cone-like, bright purple-blue flowers on strong stems in summer and autumn. Height 1m (3ft), Spread 50cm (1.5ft).

Eryngium planum (Sea Holly)

A clump-forming, evergreen perennial with rosettes of toothed, dark grey-green leaves and, in summer, upright, branched stems bearing cone-like, light blue flower-heads with conspicuous, linear, spiny, blue-green bracts.

Eryngium variifolium (Moroccan Sea Holly)

An erect herbaceous perennial with, white-marbled, dark green leaves and grey-blue to pale blue, teasel-like flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

Eupatorium maculatum 'Atropurpureum'

A large, robust herbaceous perennial with purple stems, whorled, oval leaves and flat, terminal clusters of small, reddish-purple flowers borne on erect stems in summer. Height 2.5m (8ft), Spread 1m (3ft).

Eupatorium maculatum 'Riesenschirm' (Joe-Pye Weed)

A vigorous, upright, clump-forming, herbaceous perennial with dark purple stems bearing whorled, elliptic, dark green leaves and terminal clusters of small, purple-pink flowers in summer. Height 2m (6ft), Spread 1m (3ft).

Euphorbia amygdaloides var. robbiae (Mrs Robb's Bonnet)

A spreading, evergreen perennial with rosettes of oblong, leathery, glossy, dark green leaves and cymes of yellow-green flowers from mid-spring to early summer. Height 50cm (1.5ft), Spread 1m (3ft).

Euphorbia characias subsp. wulfenii 'Shorty'

An upright, bushy, evergreen perennial or subshrub bearing dense whorls of linear, blue-green leaves, flushed red when young, and, in spring, small green flowers surrounded by large, bright yellow to yellow-green bracts.

Euphorbia characias subsp. wulfenii (Mediterranean Spurge)

An upright, evergreen shrub with biennial shoots bearing linear to oblong, grey-green leaves and dense, spherical to cylindrical cymes of yellow-green flowers from early spring to early summer. Height & Spread 1.2m (4ft).

Euphorbia x martinii 'Ascot Rainbow' (Spurge)

An evergreen perennial with whorls of grey-green lance-shaped leaves edged in yellow. In cooler months, the foliage becomes flushed with shades of red, pink & orange. Clusters of lime-green flowers in early spring.

Filipendula rubra 'Venusta' (Meadowsweet)

An erect, spreading, clump-forming perennial with bright green leaves and, in early and midsummer, crowded, terminal clusters of fragrant, rose-pink flowers that fade to pink with age.

Gaura lindheimeri

A perennial with slender, tall stems with small, dark-green leaves and starry white flowers flushed pink in late summer and early autumn. Height 1.5m (5ft), Spread 1m (3ft).

Gaura lindheimeri 'Belleza'

An upright to compact, bushy perennial with tall stems bearing narrow, mid-green leaves and, from early summer into autumn, wand-like panicles of light pink, dark pink, or white flowers. Height 1m (3ft), Spread 60cm (2ft).

Gaura lindheimeri 'Cherry Brandy'

A compact, clump-forming, deciduous perennial with upright stems bearing dark green leaves, flushed red when young, and wand-like panicles of star-shaped, pale pink flowers from early summer into autumn.

Gaura lindheimeri 'Rosyjane'

A bushy, clump-forming perennial with erect stems bearing small leaves and bi-coloured flowers in white with a picotee edge of cerise-pink blooming from late spring to autumn. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Geranium 'Azure Rush'

A compact, mound-forming, herbaceous perennial with rounded, deeply-lobed, dark green leaves and erect, branching stems bearing single, cup-shaped, veined, lavender-blue flowers from summer into autumn.

Geranium 'Brookside' (Cranesbill)

A vigorous, spreading, deciduous perennial with lobed leaves and long-stems bearing large, rounded, dark-veined, lavender-blue flowers. Height 60cm (2ft), Spread 1m (3ft).

Geranium 'Rozanne' (Cranesbill)

A mound-forming perennial with marbled leaves that have a soft velvety texture and large, cupped, blue flowers with white centres and maroon veins in late summer. Height 60cm (2ft), Spread 1m (3ft).

Geranium clarkei 'Kashmir White'

A spreading herbaceous perennial with divided leaves and small white flowers veined with purple-pink in summer. Height 50cm (1ft), Spread 1m (3ft).

Geranium macrorrhizum 'Bevan's Variety' (Cranesbill)

A rhizomatous, semi-evergreen perennial with lobed, toothed, aromatic, sticky, light green leaves and clusters of purple-pink flowers in early summer. Height & Spread 50cm (1.5ft).

Geranium sanguineum 'Vision Violet' (Bloody Cranesbill)

A mat-forming, herbaceous perennial with dark green leaves turning orange-red in autumn, and cup-shaped, purple-pink flowers from late spring into summer with sporadic blooms until autumn. Height & Spread 50ccm (1.5ft).

Geranium x cantabrigiense 'Biokovo' (Mountain Cranesbill)

A compact, slowly spreading, evergreen perennial with aromatic, glossy, light green leaves, turning red and yellow in autumn, and dense clusters of flat, pink-flushed, white flowers from late spring to late summer.

Geranium x oxonianum 'Wargrave Pink'

An evergreen perennial with a clump-forming habit. Its mid-green leaves are divided into five lobes. From early summer through to autumn it bears pale salmon-pink flowers. Height 60cm (2ft), Spread 1m (3ft).

Geum 'Banana Daiquiri' (Avens)

A mound-forming, deciduous to semi-evergreen perennial with hairy, mid- to dark green basal leaves and slender stems bearing semi-double, yellow flowers from late spring into summer. Height 50cm (1.5ft), Spread 30cm (1ft).

Geum 'Borisii' (Avens)

A clump-forming perennial with upright, hairy, mid-green leaves and orange-red flowers on upright stems in late spring to late summer. Height 50cm (1.5ft), Spread 30cm (1ft).

Geum 'Coral Tempest' (Avens)

A mound-forming, deciduous to semi-evergreen perennial with mid- to dark green leaves and slender, wiry stems bearing semi-double, saucer-shaped, salmon to orange-red flowers from late spring into summer.

Geum 'Lady Stratheden' (Avens)

A herbaceous perennial with mound forming, green, hairy, kidney shaped leaves and semi-double, rich yellow flowers on branched stems throughout summer. Height & Spread 50cm (1.5ft).

Geum 'Mai Tai' (Avens)

A clump-forming, herbaceous perennial with pinnate, hairy, mid-green basal leaves and slender, burgundy stems bearing semi-double, frilled, pink-flushed, apricot flowers from late spring into midsummer.

Geum 'Mrs J. Bradshaw' (Avens)

A clump-forming herbaceous perennial with hairy, dark-green, basal leaves and purple stems bearing semi-double, orange-red flowers in summer. Height 60cm (2ft), Spread 50cm (1.5ft).

Geum 'Pink Petticoats' (Avens)

A mound-forming, deciduous to semi-evergreen perennial with mid- to dark green basal leaves and slender, wiry stems bearing semi-double, saucer-shaped, ruffled, pink to coral-pink flowers from mid-spring to early autumn.

Geum 'Prinses Juliana' (Avens)

A clump-forming, deciduous perennial with hairy, lobed, dark green, basal leaves and purple stems bearing semi-double, bright orange flowers in summer. Height & Spread 60cm (2ft).

Geum 'Scarlet Tempest' (Avens)

A mound-forming, evergreen to semi-evergreen perennial with pinnate, toothed, hairy, mid- to dark green basal leaves and slender stems bearing orange-flushed, red flowers from late spring into autumn.

Geum 'Tempo Yellow' (Avens)

A mound-forming, deciduous to semi-evergreen perennial with mid-green leaves and, from late spring into summer, slender, wiry stems bearing semi-double, saucer-shaped, yellow flowers with maroon calyces.

Geum 'Tequila Sunrise' (Avens)

A clump-forming, herbaceous perennial with mid-green leaves & slender, reddish-purple stems bearing single to semi-double, red-flushed, yellow to apricot flowers from late spring into summer. Height & Spread 50cm (1.5ft).

Geum coccineum (Avens)

A clump-forming, deciduous perennial with upright, softly hairy, dark green leaves and, from late spring to late summer, cymes of orange or red flowers with spreading petals and prominent, yellow stamens.

Gypsophila cerastioides 'Pretty Maid' (Baby's Breath)

A dwarf, semi-evergreen perennial. It is a creeping plant, forming tufts of grey-green, hairy leaves. From late spring to early summer, it produces small, pink-flushed, fragrant, white, trumpet shaped flowers.

Helenium autumnale 'Salud Embers' (Sneezeweed)

A compact, upright, deciduous perennial with branching stems bearing hairy, sparsely toothed, dark green leaves and orange-red flowers with yellow edges from summer into autumn. Height & Spread 50cm (1.5ft).

Helenium autumnale 'Short and Sassy' (Sneezeweed)

A compact, clump-forming, herbaceous perennial with oblong to lance-shaped, dark green leaves and, from midsummer to early autumn, orange and bright yellow flowers with brown central cones.

Hemerocallis 'Bonanza' (Daylily)

A herbaceous perennial with long, strap-like green leaves and large, golden-orange flowers distinctively marked with a red throat in summer. Height 75cm (2.5ft), Spread 1m (3ft).

Hemerocallis 'Catherine Woodbery' (Daylily)

A clump-forming, semi-evergreen perennial with green leaves and, in summer, slender, erect stems bearing star-shaped, pale pink to pale lavender-pink flowers with lightly ruffled petals and wide, lime-green throats.

Hemerocallis 'Crimson Pirate' (Daylily)

A clump forming, herbaceous perennial with green, strap-like leaves and striking, vivid red flowers with a yellow throat in late summer. Height & Spread 1m (3ft).

Hemerocallis 'Stella De Oro' (Day Lily)

A vigorous, herbaceous perennial with mid-green, strap-shaped leaves. It is free-flowering, producing golden-yellow, fragrant, funnel-shaped flowers, throughout summer. Height 30cm, Spread 50cm (1.5ft).

Hemerocallis fulva var. kwanso (Daylily)

A semi-evergreen, clump-forming perennial with narrow, strap-like, dark green leaves and, in summer, double, orange, trumpet-shaped flowers with a burgundy blush. Height 1m (3ft), Spread 50cm (1.5ft).

Heuchera 'Black Pearl' (Alum Root)

A compact, mound-forming, semi-evergreen to evergreen perennial bearing ruffled, glossy, dark purple-black leaves and slender, upright stems bearing open panicles of white flowers from early summer into autumn.

Heuchera 'Carnival Cocomint' (Alum Root)

A compact, mound-forming, semi-evergreen to evergreen perennial bearing lobed, rounded, silvery, bright green leaves with dark burgundy veins. Height & Spread 30cm (1ft).

Heuchera 'Chocolate Ruffles' (Alum Root)

A perennial forming heart shaped, chocolate brown leaves on top with burgundy undersides peeking out from each ruffle and sprays of white, tubular-shaped flowers on purple stems. Height & Spread 30cm (1ft).

Heuchera 'Fire Chief' (Alum Root)

A clump-forming, mounded, semi-evergreen to evergreen perennial with ruffled, dark red to purple-red leaves and dark red stems bearing small, pink-flushed, white flowers in late spring, and again from summer into autumn.

Heuchera 'Grape Timeless' (Alum Root)

A compact, mound-forming, semi-evergreen to evergreen perennial bearing purple leaves with dark veins and slender, upright stems bearing panicles of star-shaped, bright rose-pink flowers from mid-spring into summer.

Heuchera 'Indian Summer Boysenberry' (Alum Root)

A compact, mound-forming, semi-evergreen perennial bearing rounded, ruffled, lobed, reddish-brown to orange-red leaves, and upright stems bearing panicles of small, bell-shaped, white flowers from late spring into summer.

Heuchera 'Lime Marmalade' (Alum Root)

A mound-forming, semi-evergreen to evergreen, herbaceous perennial with ruffled, lime- to yellow-green leaves and tall, slender stems bearing panicles of tiny, bell-shaped, pale brown flowers from late spring into summer.

Heuchera 'Marmalade' (Alum Root)

A clump-forming, evergreen perennial with red stems bearing ruffled leaves that emerge copper-red or pink and turn bronze or golden-yellow with maturity. Small, bell-shaped, red-brown flowers on upright stems in summer.

Heuchera 'Midnight Rose' (Alum Root)

A mound-forming, semi-evergreen perennial with dark burgundy foliage splattered pink. The pink lightens to cream as summer progresses. Height & Spread 50cm (1.5ft).

Heuchera 'Obsidian' (Alum Root)

A clump-forming, semi-evergreen perennial with smooth, glossy, rounded, lobed, dark purple-black leaves and tall red stems bearing loose panicles of ivory flowers in summer. Height & Spread 50cm (1.5ft).

Heuchera 'Silver Scrolls' (Alum Root)

A compact, clump-forming, semi-evergreen perennial with ruffled, silvery, red-purple leaves and small pale green flowers in summer. Height & Spread 50cm (1.5ft).

Heuchera 'Timeless Night' (Coral Bells)

A clump-forming, semi-evergreen perennial forming a small mound of lobed, deep-purple leaves and panicles of pink, globular flowers on purple stems in summer. Height & Spread 50cm (1.5ft).

Heuchera 'Wildberry'

A compact, mound-forming, semi-evergreen to evergreen perennial bearing glossy, rich, deep purple leaves with dark veins and upright stems bearing tiny, star-shaped, creamy-white flowers from late spring into summer.

Heuchera americana 'Plum Pudding' (Alum Root)

A low-growing perennial that forms heart shaped, lobed, plum leaves with darker plum veining and panicles of white, tubular-shaped flowers on purple stems. Height & Spread 50cm (1.5ft).

Heuchera micrantha 'Palace Purple' (Alum Root)

A mound-forming, semi-evergreen perennial with ivy-like, purple leaves with red undersides. Panicles of small, pinkish-white, bell-shaped flowers are borne on slender, dark-red stems in late spring to early summer.

Heucherella 'Alabama Sunrise' (Foamy Bells)

A clump-forming, semi-evergreen perennial. It has rounded leaves with cut margins that emerge yellow-green in spring, darken to green in summer then take on orangey-pink tints in autumn.

Heucherella 'Buttered Rum' (Foamy Bells)

A mound-forming, semi-evergreen to evergreen perennial bearing maple-like, lobed leaves in shades of orange, yellow, and red. Slender stems bear panicles tiny, bell-shaped, cream flowers from late spring into summer.

Heucherella 'Red Rover'

A mound-forming, semi-evergreen to evergreen perennial bearing lobed, intense red leaves, coppery red when young, and slender, upright stems bearing dense panicles of creamy-white flowers from summer into autumn.

Hosta 'August Moon' (Plantain Lily)

A medium to large sized, mounding, deciduous perennial with large, heart-shaped, gold foliage with slightly rippled margins and white to pale lavender flowers in summer. Height 60cm (2ft), Spread 1m (3ft).

Hosta 'Diana Remembered' (Plantain Lily)

A clump-forming, herbaceous perennial bearing broadly ovate, lightly puckered, grey-green leaves with wide, irregular, creamy-white margins and slender scapes bearing racemes of fragrant, tubular, white flowers in summer.

Hosta 'Frances Williams' (Plantain Lly)

A clump-forming perennial with heart-shaped, puckered and veined grey-green leaves with wide yellow-green edges. Pale lilac flowers form in compact racemes. Height & Spread 1m (3ft).

Hosta 'Guacamole' (Plantain Lily)

A clump-forming, herbaceous perennial producing a mound of golden-yellow to light green leaves with dark green margins. Funnel-shaped, fragrant, white to lavender flowers bloom on tall stems in summer. Sun tolerant.

Hosta 'Halcyon' (Plantain Lily)

A compact, mound-forming, deciduous perennial with thick, ovate, blue-green to blue-grey leaves and sturdy, erect scapes bearing bell-shaped, silvery, pale lavender flowers in summer. Height 60cm (2ft), Spread 1m (3ft).

Hosta 'Night Before Christmas'

A clump-forming, herbaceous perennial producing a mound of glossy, ovate to heart-shaped, slightly twisted, dark-green leaves with creamy-white centres. Funnel-shaped, pale lavender flowers bloom on tall stems in summer.

Hosta 'Patriot' (Plantain Lily)

A perennial of a clump-forming habit with rounded, heart-shaped leaves edged in white and, in summer, it bears lavender flowers on erect leafy stems. Height & Spread 50cm (1.5ft).

Hosta 'Wide Brim' (Plantain Lily)

A perennial with a clump-forming habit. Its heart-shaped leaves are dark-green margined with creamy-yellow. In summer it bears funnel-shaped, pale lavender flowers on erect stems. Height 50cm (1.5ft), Spread 1m (3ft).

Hosta fortunei var. aureomarginata (Plantain Lily)

A deciduous, clump-forming perennial with large, variegated, bright green, heart-shaped leaves that have broad, creamy-yellow edges and trumpet-shaped, mauve flowers in late summer. Height & Spread 1m (3ft).

Hosta sieboldiana var. elegans

A clump-forming perennial with large, rounded, heart-shaped, grey-blue leaves and spikes of lilac-tinged, trumpet-shaped, white flowers in late summer. Height & Spread 1m (3ft).

Houttuynia cordata 'Chameleon' (Heart-Leaved Houttuynia)

A mat-forming, spreading, herbaceous perennial with showy splashes of cream yellow, pink, & red on the leaves and white flower spikes in late spring. Height 30cm (1ft), Spread 1m (3ft).

Iris 'Alcazar' (Tall Bearded Iris)

A hardy, large bulbous perennial with strong, green, upright foliage and fragrant, rich purple flowers with a golden beard and lavender upper petals. Height 1m (3ft), Spread 30cm (1ft).

Iris 'Immortality' (Bearded Iris)

A clump-forming, rhizomatous perennial with upright, strap-like, dark green leaves and white flowers with yellow beards blooming in spring and again from late summer to mid-autumn. Height 1m (3ft), Spread 60cm (2ft).

Iris 'Jane Phillips'

A clump-forming, rhizomatous perennial with upright, strap-like, grey-green leaves and, in early summer, pale violet-blue flowers with paler, veined falls. Height 1m (3ft), Spread 50cm (1.5ft).

Iris 'Red Orchid'

A clump-forming, rhizomatous, semi-evergreen perennial with sword-shaped, grey-green leaves and, in late spring and early summer, sturdy, upright stems bearing large, maroon to reddish-purple flowers with yellow beards.

Iris 'Rocket'

A clump-forming, herbaceous perennial with strap-shaped leaves and sweetly scented, ruffled amber, buff-yellow flowers in spring. Height 75cm (2.5ft), Spread 30cm (1ft).

Iris 'Sultan's Palace'

A clump-forming, rhizomatous perennial with upright, strap-like, grey-green leaves and, in early summer, rich maroon red flowers. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Iris lazica (Lazistan Iris)

A clump-forming, rhizomatous, evergreen perennial with arching, glossy, narrowly lance-shaped, bright green leaves and, in early spring, lavender-blue to deep purple flowers with white-marked, spotted falls.

Iris pallida 'Argentea Variegata' (Sweet Iris)

A perennial bearded Iris with semi-evergreen, upright, sword-like foliage that is blue-green striped with cream and white. In early summer it produces fragrant, soft blue flowers. Height 60cm (2ft), Spread 50cm (1.5ft).

Iris pseudacorus (Yellow Flag)

An extremely vigorous, rhizomatous, deciduous perennial forming an extensive clump of erect, sword-shaped, grey-green leaves and, in summer bright yellow flowers with brown or purple- veined falls.

Iris sibirica 'Ruffled Velvet' (Siberian Iris)

A perennial, rhizomatous Iris that features upright, strap-like, semi-evergreen, dark green foliage. It has medium-sized, deep purple flowers on tall stalks in early summer. Height 75cm (2.5ft), Spread 60cm (2ft).

Iris sibirica 'Silver Edge' (Siberian Iris)

A perennial, rhizomatous Iris that features upright, strap-like, semi-evergreen, blue-green foliage. It has medium-sized, mid-blue flowers with silver, ruffled edges in early summer. Height 75cm (2.5ft), Spread 60cm (2ft).

Iris sibirica 'Snow Queen' (Siberian Iris)

An upright herbaceous perennial with narrow, strap-shaped, green leaves and white, beardless flowers with purple veins that bloom in late spring. Height & Spread 1m (3ft).

Kirengeshoma palmata (Yellow Wax Bells)

A clump-forming, deciduous perennial with arching, maroon stems bearing lobed, slightly hairy, light green leaves and nodding cymes of fleshy, broadly tubular, pale yellow flowers in late summer and early autumn.

Knautia macedonica 'Red Knight' (Macedonian Scabious)

An upright, clump-froming, herbaceous perennial with slender, branched stems, pinnately lobed basal leaves and, in summer, numerous, long-lasting red flowerheads in summer. Height 1m (3ft), Spread 30cm (1ft).

Knautia macedonica (Macedonian Scabious)

An upright, clump-forming herbaceous perennial with slender, branched, leafy stems, pinnately lobed basal leaves and a profusion of long-lasting, dark red flowerheads in summer. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Kniphofia 'Ice Queen' (Red Hot Poker)

A vigorous, upright, deciduous perennial with strap-shaped, dark green leaves and sturdy, erect, stems bearing spikes of green buds opening to tubular, pale yellow flowers in autumn. Height 1.5m (5ft), Spread 75cm (2.5ft).

Kniphofia 'Little Maid' (Red Hot Poker)

A clump-forming, herbaceous perennial with arching, grass-like, mid-green leaves and spike-like racemes of pale green buds opening to pale-yellow flowers fading to cream in summer and autumn.

Kniphofia 'Nancy's Red' (Red Hot Poker)

A clump-forming, upright perennial with tall stems, grassy green leaves, and tubular spikes of dusty red-orange flowers in summer. Height & Spread 50cm (1.5ft).

Kniphofia 'Royal Castle' (Red Hot Poker)

A vigorous, upright, evergreen or semi-evergreen perennial with strap-shaped, dark green leaves and sturdy, erect, stems bearing spikes of bright orange, red, or yellow flowers from summer into autumn.

Lamium maculatum 'White Nancy' (Spotted Deadnettle)

A mat-forming, deciduous perennial with bearing rough, heart-shaped, silvery-grey leaves with dark green margins. Short spikes of whorled, tubular, two-lipped, white flowers bloom in summer.

Leucanthemum 'Goldfinch' (Shasta Daisy)

A herbaceous perennial with glossy, dark-green, oblong leaves. Throughout summer it bears semi-double, lemon yellow daisy-like flowers that gradually mature to ivory white. Height 60cm (2ft), Spread 50cm (1.5ft).

Leucanthemum x superbum 'Aglaia' (Shasta Daisy)

A herbaceous perennial with dark green, glossy leaves. In summer and autumn it bears large, white, semi-double, daisy-like flowers with yellow centres. Height 60cm (2ft), Spread 50cm (1.5ft).

Leucanthemum x superbum 'Becky' (Shasta Daisy)

A vigorous, upright, clump-forming, herbaceous perennial with mid-green basal leaves and, from midsummer into autumn, upright stems bearing large, white flowers with yellow centres. Height & Spread 1m (3ft).

Leucanthemum x superbum 'Broadway Lights' (Shasta Daisy)

A herbaceous perennial with dark green, glossy leaves and canary yellow, daisy-like flowers which then fade to white in summer and autumn. Height & Spread 50cm (1.5ft).

Leucanthemum x superbum 'LaCrosse' (Shasta Daisy)

A clump-forming herbaceous perennial with dark green, toothed, lance-shaped leaves. Single white flowers with yellow centres, sometimes spoon shaped petals, flowering for a long period in the summer.

Leucanthemum x superbum 'Laspider' (Shasta Daisy)

A compact, clump-forming, deciduous perennial with toothed, glossy, dark green leaves and, in summer and autumn, sturdy, upright stems bearing large, double, white flowers with notched petals and yellow centres.

Leucanthemum x superbum 'Silver Princess' (Shasta Daisy)

A dwarf, herbaceous perennial with dark green, glossy leaves and in summer and autumn bears white, daisy-like flowers with a yellow centre. Height & Spread 50cm (1.5ft).

Leucanthemum x superbum 'Spellbook Lumos' (Shasta Daisy)

A dwarf, clump-forming, herbaceous perennial with glossy, dark green leaves and, from summer to early autumn, upright stems bearing large, pale yellow flowers with golden-yellow centres. Height & Spread 60cm (2ft).

Liatris spicata 'Alba' (Button Snakewort)

A clump-forming perennial with linear to lance-shaped, mid-green leaves and erect, dense spikes of white flowerheads from summer into early autumn. Height 1.5m (5ft), Spread 50cm (1.5ft).

Liatris spicata 'Kobold' (Button Snakewort)

A small, compact, upright, clump-forming perennial with narrow foliage and deep purple, fluffy, terminal flower spikes that appear throughout summer. Height 60cm (2ft), Spread 30cm (1ft).

Ligularia stenocephala 'The Rocket' (Golden Groundsel)

A herbaceous perennial with large, toothed, heart-shaped, dark green leaves and tall dense racemes of yellow flowers on black stems in summer. Height 2m (6ft), Spread 1m (3ft).

Lilium 'Abbeville's Pride' (Asiatic Lily)

A compact, erect, bulbous perennial with a sturdy stem bearing elliptic, glossy, dark green leaves and, in summer, upward-facing, bright orange flowers. Height 50cm (1.5ft), Spread 20cm (8in).

Lilium 'Elgrado' (Asiatic Lily)

A compact, erect, bulbous perennial with a sturdy stem bearing elliptic, glossy, dark green leaves and, in summer, upward-facing, dark red flowers. Height 60cm (2ft), Spread 30cm (1ft).

Lilium 'Fire King'

A clump-forming bulbous perennial with leafy upright stems. In summer, it bears deep orange, funnel-shaped flowers with recurved petals that have purple freckles. Height 1m (3ft), Spread 30cm (1ft).

Lilium 'Foxtrot' (Asiatic Lily)

A compact, erect, bulbous perennial with a sturdy stem bearing elliptic, glossy, dark green leaves and, in summer, masses of upward-facing, light pink flowers. Height 50cm (1.5ft), Spread 20cm (8in).

Lilium 'Inuvik' (Asiatic Lily)

A compact, erect, bulbous perennial with a sturdy stem bearing elliptic, glossy, dark green leaves and, in summer, upward-facing, white flowers with lightly spotted, green throats. Height 50cm (1.5ft), Spread 30cm (1ft).

Lilium regale 'Royal Gold' (Regal Lily)

A bulbous perennial with narrow, glossy, green leaves and large, trumpet-shaped, golden-yellow flowers. Height 1m (3ft), Spread 50cm (1.5ft).

Liriope muscari 'Royal Purple' (Big Blue Lilyturf)

A clump-forming, tuberous, evergreen perennial with arching, glossy, dark green leaves and erect, deep purple flowers in late summer and autumn, followed by bright purple berries. Height 30cm (1ft), Spread 50cm (1.5ft).

Lobelia cardinalis 'Queen Victoria' (Cardinal Flower)

A herbaceous perennial with dark red, oblong leaves and spikes of bright scarlet, two-lipped flowers in late summer and autumn. Height 1m (3ft), Spread 60cm (2ft).

Lobelia x speciosa 'Sparkling Ruby'

A clump-forming, slightly hairy perennial with ovate to oblong, mid-green leaves and erect, leafy, terminal racemes of double lipped, ruby red to dark red flowers in summer and autumn. Height 1m (3ft), Spread 60cm (2ft).

Lobelia x speciosa 'Starship Scarlet'

A compact, upright, bushy perennial with upright stems bearing ovate to lance-shaped, bronze-green leaves and terminal racemes of two-lipped, bright scarlet red flowers from summer into autumn.

Lupinus 'Gallery Blue' (Lupin)

A compact, bushy, herbaceous perennial with attractive, mid-green, palmate leaves. In summer, it bears densly-packed, upright racemes of pea-like flowers in shades of blue. Height & Spread 50cm (1.5ft).

Lupinus 'Gallery Pink' (Lupin)

A dwarf, clump-froming, herbaceous perennial with mid-green, palmate leaves and tall, upright, terminal racemes of pink flowers from spring until summer. Height 60cm (2ft), Spread 30cm (1ft).

Lupinus 'Gallery Red' (Lupin)

A dwarf, clump-forming, herbaceous perennial with palmate, mid-green leaves and tall, upright, terminal racemes of dark red flowers in summer. Height 60cm (2ft), Spread 30cm (1ft).

Lupinus 'Gallery Yellow' (Lupin)

A dwarf, clump-forming, herbaceous perennial with palmate, mid-green leaves and tall, upright, terminal racemes of pale yellow flowers from spring until summer. Height 60cm (2ft), Spread 30cm (1ft).

Lupinus 'King Canute' (Lupin)

A vigorous, upright, clump-forming, herbaceous perennial with palmate, mid- to bright green leaves and large, erect, terminal racemes of dark blue and white flowers in summer. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Lupinus 'Polar Princess' (Lupin)

A compact, clump-forming perennial with palmate, mid-green leaves and tall, upright, terminal racemes of white flowers in summer. Height & Spread 75cm (2.5ft).

Lupinus 'Red Rum' (Lupin)

A robust, clump-forming, herbaceous perennial with palmate, mid-green leaves and erect, terminal racemes of white-flecked, red flowers from late spring into summer. Height 1m (3ft), Spread 50cm (1.5ft).

Lupinus 'Towering Inferno' (Lupin)

A vigorous, upright, clump-forming, herbaceous perennial with palmate, mid- to bright green leaves and large, erect, terminal racemes of deep orange to orange-red flowers in summer. Height 1m (3ft), Spread 60cm (2ft).

Lychnis chalcedonica (Maltese Cross)

A herbaceous perennial with bright green leaves on upright stems bearing masses of bright red flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

Monarda didyma 'Balmy Lilac' (Bergamot)

A compact, mound-forming, herbaceous perennial with aromatic, semi-glossy, dark green leaves and erect stems bearing dense clusters of tubular, deep lilac to lilac-pink flowers in summer. Height & Spread 30cm (1ft).

Monarda didyma 'Balmy Pink' (Bergamot)

A compact, clump-forming, herbaceous perennial with pointed, toothed, aromatic, dark green leaves and erect stems bearing dense, whorled clusters of tubular, two-lipped, pink flowers in summer. Height & Spread 30cm (1ft).

Monarda didyma 'Balmy Purple' (Bergamot)

A compact, clump-forming, deciduous perennial with aromatic, dark green leaves and erect stems bearing dense, whorled clusters of tubular, two-lipped, dark magenta to reddish-purple flowers from midsummer into autumn.

Nepeta 'Six Hills Giant' (Catmint)

A hardy perennial with aromatic, grey-green foliage and short, purple flower spikes in summer. Height & Spread 1m (3ft).

Nepeta racemosa 'Walker's Low' (Dwarf Catmint)

An erect perennial with aromatic foliage, producing spikes of blue, tubular flowers in summer. Height & Spread 50cm (1.5ft).

Nepeta x faassenii 'Purrsian Blue' (Garden Catmint)

A compact, mound-forming, herbaceous perennial with small, hairy, aromatic, toothed, grey-green leaves and, from early summer to early autumn, numerous, erect spikes of blue flowers with dark purple calyces.

Nerine bowdenii (Bowden-Cornish Lily)

A robust, summer-dormant, bulbous perennial with strap-shaped, rich green leaves and, in autumn, usually before the leaves emerge, erect stems bearing open clusters of funnel-shaped, pink flowers.

Paeonia 'Felix Crousse' (Peony)

A clump-forming, rounded to upright perennial with erect stems bearing deep green leaves &, in late spring & early summer, large, fragrant, double, reddish-pink flowers with dark centres & ruffled, silver-margined petals.

Paeonia 'Monsieur Jules Elie' (Peony)

An upright, bushy, herbaceous perennial with dark green leaves and, from late spring into summer, strong, erect stems bearing large, rounded, double, deep rose-pink flowers with a silvery sheen. Height & Spread 1m (3ft).

Paeonia 'Shirley Temple' (Double Peony)

An upright, bushy, herbaceous perennial with divided, dark green leaves and, in late spring and early summer, sturdy, erect stems bearing large, double, white flowers. Height 2.5m (8ft), Spread 1.5m (5ft).

Paeonia lactiflora 'Dancing Butterfly' (Peony)

An upright, bushy, herbaceous perennial with dark green leaves and, in early summer, sturdy, erect stems bearing large, fragrant, single, pink flowers with yellow stamens. Height & Spread 1m (3ft).

Paeonia lactiflora 'Doctor Alexander Fleming' (Peony)

A clump-forming, herbaceous perennial bearing red-mottled stems, dark green leaves with lance-shaped leaflets and, in summer, fragrant, double, rose-pink flowers with curled inner petals. Height & Spread 1m (3ft).

Paeonia lactiflora 'General MacMahon' (Peony)

A clump-forming, herbaceous perennial bearing red-mottled stems, dark green leaves with lance-shaped leaflets and, in summer, fragrant, double, crimson flowers with curled inner petals. Height & Spread 1m (3ft).

Paeonia lactiflora 'Kansas' (Peony)

A clump-forming, herbaceous perennial with divided, dark green leaves and, in late spring and early summer, sturdy, erect stems bearing large, fragrant, double, bright reddish-pink flowers.

Paeonia lactiflora 'Karl Rosenfield' (Peony)

A herbaceous perennial with attractive, divided, mid-green leaves. In late spring and early summer, it bears large, double, crimson flowers. Height & Spread 75cm (2.5ft).

Paeonia lactiflora 'Miss Mary' (Peony)

An upright, bushy, herbaceous perennial with dark green leaves and, from late spring into summer, strong, erect stems bearing large, cup-shaped, richly fragrant, single, deep red flowers with yellow stamens.

Paeonia lactiflora 'Sarah Bernhardt' (Peony)

A herbaceous perennial with large, fragrant, rose-pink double flowers with ruffled inner petals. Height 2.5m (8ft), Spread 1.5m (5ft).

Papaver nudicaule (Arctic Poppy)

A short-lived perennial, often grown as an annual, with large, papery, bowl-shaped, lightly fragrant flowers. Varieties come in flower shades of yellow, orange, salmon, rose, pink, cream and white.

Papaver orientale 'Royal Wedding' (Oriental Poppy)

An upright herbaceous perennial with divided, grey-green leaves and large, fluffy, papery, solitary, white flowers with purple-black blotches at the base of each petal. Height 1m (3ft), Spread 50cm (1.5ft).

Penstemon 'Blackbird'

An upright perennial with lush green foliage and tubular-shaped, deep-purple flowers with a white striped throat from early summer. Height 1m (3ft), Spread 50cm (1.5ft).

Penstemon 'Pensham Amelia Jane'

A bushy, clump-forming, semi-evergreen perennial with linear to lance-shaped, mid-green leaves and, from summer into autumn, upright racemes of tubular, red flowers with white throats. Height 1m (3ft), Spread 60cm (2ft).

Penstemon 'Pensham Arctic Fox'

A compact, bushy, semi-evergreen perennial with linear to lance-shaped, mid-green leaves and upright racemes of small, tubular, white flowers from midsummer to mid-autumn. Height 50cm (1.5ft), Spread 60cm (2ft).

Penstemon 'Pensham Plum Jerkum'

A bushy, semi-evergreen perennial with lance-shaped, green leaves and, from midsummer into autumn, upright racemes of small, tubular, dark purple flowers with white mottled throats. Height 75cm (2.5ft), Spread 60cm (2ft).

Penstemon 'Pensham Wedding Day'

A bushy, clump-forming, semi-evergreen perennial with linear to lance-shaped, mid-green leaves and upright racemes of tubular, white flowers from midsummer to mid-autumn. Height 75cm (2.5ft), Spread 60cm (2ft).

Persicaria affinis 'Darjeeling Red' (Knotweed)

A mat-forming, semi-evergreen perennial with large, elliptic to lance-shaped, dark green leaves and, from midsummer to mid-autumn, erect spikes of pink flowers that turn red as they mature.

Persicaria affinis 'Donald Lowndes' (Knotweed)

A low-growing, semi-evergreen perennial with dark-green foliage and flower spikes in summer and autumn that emerge light pink and mature with age to dark pink. Height 20cm (8in), Spread 50cm (1.5ft).

Persicaria amplexicaulis 'Rosea' (Red Bistort)

A robust, upright, clump-forming perennial with large, ovate to lance-shaped, pointed, prominently-veined, mid-green leaves and narrow, long-stalked spikes of pink flowers from midsummer to early autumn.

Persicaria bistorta 'Superba' (Knotweed)

A mat-forming, semi-evergreen perennial with large, ovate foliage and spikes of large, white bottlebrush flowers from late-summer to early-autumn. Height 75cm (2.5ft), Spread 1m (3ft).

Phlomis fruticosa (Jerusalem Sage)

A low-growing perennial with sage-like, grey-green ovate leaves and hooded, deep yellow flowers. Height 1m (3ft), Spread 1.5m (5ft).

Phlox paniculata 'Pink Flame'

A compact, bushy mound-forming, herbaceous perennial with broadly lance-shaped, dark green leaves and, in summer, upright panicles of fragrant, pink flowers with dark pink eyes. Height 50cm (1.5ft), Spread 30cm (1ft).

Phlox paniculata 'Purple Flame'

A compact, upright, clump-forming, herbaceous perennial with dark green leaves, and, from summer into early autumn, upright panicles of fragrant, purple flowers with red eyes. Height & Spread 50cm (1.5ft).

Physalis alkekengi 'Halloween Queen' (Cape Gooseberry)

A compact perennial with bright green foliage and clusters of small, white flowers in summer followed by small edible fruits contained in bright orange-red, paper-thin Chinese Lanterns. Height & Spread 50cm (1.5ft).

Physostegia virginiana 'Rosea' (Obedient Plant)

An upright, spreading, herbaceous perennial with lance-shaped, toothed, dark green leaves and dense, spike-like racemes of tubular, pink flowers from midsummer into early autumn. Height 1m (3ft), Spread 60cm (2ft).

Primula auricula 'Black Jack' (Auricula)

A semi-evergreen, clump-forming, herbaceous perennial with powdery, pale grey leaves. It produces deep burgundy flowers with a white-rimmed yellow center from mid-spring through to summer. Height & Spread 30cm (1ft).

Primula auricula 'Lunar Eclipse' (Auricula)

A rosette-forming, evergreen perennial with powdery, fleshy, grey-green leaves and, throughout spring, fragrant, double, copper-orange flowers with yellow eyes. Height & Spread 30cm (1ft).

Primula auricula 'Purple Pip' (Auricula)

An evergreen perennial with rosettes of pale, greyish-green leaves. Clusters of deep red-purple, double flowers appear on short, upright stems in spring. Height & Spread 50cm (1.5ft).

Primula vialii (Vial's Primrose)

An herbaceous perennial with heavily veined, oblong leaves forming a basal rosette. In early to mid-summer, it produces a single red-tipped, violet flower spike held on an upright stem.

Pulmonaria 'Blue Ensign' (Lungwort)

A perennial which forms a clump of ovate leaves, and clusters of bright blue flowers in early spring fading to purple with age. Height & Spread 30cm (1ft).

Pulmonaria 'Majeste' (Lungwort)

A clump-forming perennial with silver foliage, which bears clusters of dark pink, tubular flowers in spring. Height 30cm (1ft), Spread 60cm (2ft).

Pulmonaria 'Opal' (Lungwort)

A clump forming, herbaceous perennial that has ovate, green leaves that are evenly spotted with white and has clusters of blue and white shimmering flowers throughout spring. Height 30cm (1ft), Spread 60cm (2ft).

Pulmonaria 'Pretty in Pink' (Lungwort)

A clump-forming, deciduous to semi-evergreen perennial with dark green leaves, heavily marked with silvery-white spots. Dense clusters of funnel-shaped, rose-pink flowers bloom on short stems in spring.

Pulmonaria 'Raspberry Splash' (Lungwort)

A clump-forming, deciduous to semi-evergreen perennial with dark green leaves, heavily marked with silvery-white spots. Dense clusters of funnel-shaped, purple to reddish-pink flowers bloom on short stems in spring.

Pulmonaria 'Trevi Fountain' (Lungwort)

A clump-forming, herbaceous perennial that has clumps of green, oval leaves, with silvery blotches. In spring it produces drooping clusters of funnel-shaped, cobalt blue and purplish-pink flowers.

Pulmonaria 'Twinkle Toes' (Lungwort)

A clump-forming, herbaceous perennial that has clumps of green, oval leaves, with silvery blotches. In spring it produces drooping clusters of funnel-shaped, light blue flowers opening from purplish-pink buds.

Pulmonaria angustifolia 'Azurea' (Lungwort)

A deciduous perennial forming a clump of lance-shaped, unspotted green leaves, with pink buds opening to bright blue flowers in spring. Height 30cm (1ft), Spread 50cm (1.5ft).

Rodgersia aesculifolia (Chestnut-Leaved Rodgersia)

A robust, clump-forming, herbaceous perennial with large, deeply veined, palmate, mid-green leaves borne on woolly, red-brown stalks and large panicles of creamy-white or pink flowers in midsummer.

Rudbeckia 'Summerina Orange' (Coneflower)

An upright, bushy, clump-forming, herbaceous perennial with dark green leaves and, from early summer into autumn, daisy-like, orange flowers with red-ringed, central brown cones. Height & Spread 50cm (1.5ft).

Rudbeckia fulgida var. sullivantii 'Goldsturm'

A clump-forming, herbaceous perennial with rough, dark-green, ovate leaves and large black-eyed, single, yellow daisy flowers over a long-flowering season. Height 1m (3ft), Spread 60cm (2ft).

Rudbeckia hirta 'Sunbeckia Alicia' (Black-Eyed Susan)

An erect, clump-forming, half-hardy biennial or short-lived perennial with ovate, toothed, dark green leaves and golden-yellow flowers with dark orange markings and a dark brown centre from summer into autumn.

Rudbeckia hirta 'Sunbeckia Carla' (Black-Eyed Susan)

An erect, clump-forming, half-hardy biennial or short-lived perennial with ovate, toothed, dark green leaves & golden-yellow flowers with orange-brown markings from summer into autumn. Height & Spread 50cm (1.5ft).

Rudbeckia hirta 'Sunbeckia Ophelia' (Black-Eyed Susan)

An erect, clump-forming, half-hardy biennial or short-lived perennial with ovate, toothed, dark green leaves and golden-yellow flowers from summer into autumn. Height & Spread 50cm (1.5ft).

Salvia 'African Sky' (Sage)

An upright, deciduous to semi-evergreen perennial with aromatic, mid- to bright green leaves and, from midsummer into autumn, open whorls of tubular, two-lipped flowers with violet-blue upper petals and paler lower petals.

Salvia 'Amethyst Lips' (Sage)

A bushy, evergreen sub-shrub with small, aromatic, mid-green leaves, often turning dark-red in autumn, and racemes of two-lipped, dark purple and white flowers in summer and autumn. Height 1m (3ft), Spread 75cm (2.5ft).

Salvia 'Amistad' (Sage)

An upright, branching, woody-based perennial with ovate, hairy, toothed, aromatic, mid-green leaves and dark purple stems bearing whorled spikes of fragrant, two-lipped, dark purple flowers from early summer into autumn.

Salvia 'Cherry Lips' (Sage)

A bushy, evergreen sub-shrub with small, ovate, aromatic, mid-green leaves, often turning dark-red in autumn, and loose racemes of two-lipped, reddish-pink and white flowers in summer and autumn.

Salvia 'Kisses and Wishes' (Sage)

A tender, upright, bushy, woody-based perennial, often grown as an annual, with oblong to ovate, toothed, aromatic, dark green leaves and dark stems bearing open racemes of tubular, pink flowers from midsummer into autumn.

Salvia 'May Night' (Wood Sage)

An upright perennial with dark-green foliage and racemes of deep violet flowers in early summer. Height 1m (3ft), Spread 50cm (1.5ft).

Salvia 'Pink Amistad' (Sage)

A tender to borderline hardy, upright, branching perennial with aromatic, mid-green leaves and dark purple stems bearing whorled spikes of fragrant, two-lipped, pink flowers from midsummer to mid-autumn.

Salvia 'Red Swing' (Sage)

A compact, bushy, evergreen sub-shrub or woody-based perennial with aromatic, mid-green leaves and upright, black stems bearing terminal racemes of two-lipped, scarlet flowers from early summer into autumn.

Salvia 'Royal Bumble' (Sage)

An upright, bushy evergreen to semi-evergreen subshrub or shrubby perennial with aromatic, mid- to dark green leaves and, from late summer into autumn, dark purple stems bearing whorled, two-lipped, bright red flowers.

Salvia lyrata 'Purple Knockout' (Lyre-Leaf Sage)

A compact, herbaceous perennial, with colourful foliage, burgundy when young, turning purple in summer, and red in autumn. Slender spikes, of small, two-lipped, violet flowers bloom in summer. Height & Spread 30cm (1ft).

Salvia nemorosa 'Caradonna' (Balkan Clary)

A compact, clump-forming perennial with dark-green, toothed leaves. From summer through to early autumn, it bears spikes of violet-blue flowers on dark, upright stems. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Salvia nemorosa 'East Friesland' (Balkan Clary)

An upright, compact perennial with ovate leaves and deep violet-blue flowers with pink bracts in summer and autumn. Height & Spread 50cm (1.5ft).

Salvia nemorosa 'Sensation Blue' (Balkan Clary)

A compact, clump-forming, herbaceous perennial with ovate, toothed, aromatic, dark-green leaves and dense, erect racemes of deep blue flowers in summer. Height & Spread 50cm (1.5ft).

Salvia nemorosa 'Sensation White' (Balkan Clary)

A compact, upright, clump-forming, herbaceous perennial with ovate, toothed, aromatic, wrinkled, mid-green leaves and dense, erect racemes of white flowers in summer. Height & Spread 50cm (1.5ft).

Salvia verticillata 'Purple Rain'

A herbaceous perennial with an upright form. It has ovate, slightly hairy, mid-green basal leaves and is topped with spikes of purple flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

Salvia x jamensis 'Hot Lips' (Sage)

An evergreen sub-shrub with small, aromatic, ovate foliage which may turn dark-red in autumn and open racemes of crimson and white flowers on spikes in summer and autumn. Height & Spread 1m (3ft).

Salvia x jamensis 'Pink Lips' (Sage)

An upright, bushy, borderline hardy, semi-evergreen sub-shrub with small, ovate to elliptic, aromatic, dark green leaves and open racemes of two-lipped, pink and white flowers from summer into autumn.

Salvia x sylvestris 'Mainacht' (Wood Sage)

An upright perennial with dark-green foliage and racemes of deep violet flowers in early summer. Height 1m (3ft), Spread 50cm (1.5ft).

Sanguisorba 'Little Angel' (Great Burnet)

A compact, clump-forming perennial bearing dark green leaves with creamy-white margins and slender, erect, branching stems bearing oval spikes of deep maroon flowers throughout summer. Height & Spread 60cm (2ft).

Sanguisorba menziesii (Menzies' Burnet)

A clump-forming herbaceous perennial with glaucous, scalloped foliage and tall stems bearing dense, oval flower spikes in crimson-maroon in summer and early autumn. Height 1.5m (5ft), Spread 50cm (1.5ft).

Scabiosa 'Butterfly Blue' (Pincushion Flower)

A mounding, clump-forming perennial with fine cut, grey-green basal leaves. It has pincushion flowers that are lavender blue, standing on erect stems from spring until frost. Height & Spread 50cm (1.5ft).

Scabiosa columbaria 'Pink Mist' (Small Scabious)

An upright, branched perennial with linear or lobed grey-green leaves and pink flowers with paler centres in summer and early autumn. Height & Spread 50cm (1.5ft).

Scabiosa columbaria (Small Scabious)

An upright perennial with lobed leaves, and pale purple-blue flowers in summer and early autumn. Height 1m (3ft), Spread 50cm (1.5ft).

Scabiosa incisa 'Kudo' (Scabious)

A mound-forming, deciduous biennial or short-lived perennial with finely-divided, dark grey-green leaves and upright stems bearing pink flower heads from early summer into autumn. Height 50cm (1.5ft), Spread 60cm (2ft).

Schizostylis coccinea (Kaffir Lily)

A vigorous, clump-forming perennial with narrow, bright green leaves and spikes of open, cup-shaped, scarlet flowers in autumn. Height 60cm (2ft), Spread 30cm (1ft).

Sedum 'Mr Goodbud' (Stonecrop)

An upright, clump-forming, herbaceous perennial with purple stems bearing fleshy, light to blue-green leaves & sturdy stems bearing terminal clusters of tiny, star-shaped, purple-pink flowers from late summer into autumn.

Sedum spectabile 'Autumn Joy' (Stonecrop)

One of the finest of all upright Sedums. The umbrella-like flower heads are pink and change to a rosy red in autumn and contrasting with its green foliage. Height & Spread 50cm (1.5ft).

Sedum spectabile 'Brilliant' (Ice Plant)

A perennial forming a clump with thick stems and broad elliptic, grey-green leaves and flat cymes of dark-centred, bright pink flowers. Height & Spread 50cm (1.5ft).

Sedum spectabile 'Stardust' (Ice Plant)

A clump-forming, deciduous perennial with thick, upright, unbranched stems bearing broadly elliptic, grey-green leaves and dense, flat clusters of white flowers in summer. Height & Spread 50cm (1.5ft).

Senecio candicans 'Angel Wings' (Marine Cineraria)

An upright, bushy, borderline hardy, evergreen subshrub, often grown as an annual, with large, broadly ovate, scalloped, felted, bright silvery-grey leaves and inconspicuous clusters of yellow flowers in summer.

Sidalcea 'Elsie Heugh' (Prairie Mallow)

A mid-sized, upright, herbaceous perennial with rounded leaves at its base. In summer, it bears tall spikes of soft pink flowers. Height 1m (3ft), Spread 60cm (2ft).

Sidalcea 'Sussex Beauty' (Prairie Mallow)

A mid-sized, upright, herbaceous perennial with rounded leaves at its base. In summer, it bears tall spikes of large, candy-pink flowers. Height 1m (3ft), Spread 60cm (2ft).

Stachys byzantina 'Silver Carpet' (Woolly Betony)

A mat forming perennial that is evergreen in mild climates, with oval, woolly, silver-grey leaves, but rarely has flowers. Height 50cm (1.5ft), Spread 1.2m (4ft).

Stachys byzantina (Lamb's Ears)

A low, spreading, evergreen perennial. It has soft woolly light-grey leaves and in mid-summer, produces downy spikes of small light purple flowers which are appealing to bees. Height 60cm (2ft), Spread 1m (3ft).

Stachys lanata (Lamb's Ears)

A low, spreading, evergreen perennial. It has soft woolly light-grey leaves and in mid-summer, produces downy spikes of small light purple flowers which are appealing to bees. Height 60cm (2ft), Spread 1m (3ft).

Stachys officinalis 'Hummelo' (Betony)

A low, clump-forming, spreading, semi-evergreen perennial with basal rosettes of ovate, glossy, dark green leaves and erect stems bearing dense spikes of tiny, two-lipped, lavender-pink flowers in summer.

Symphyandra zangezura (Caucasian Ring Bellflower)

A compact, mound-forming biennial or short-lived perennial with rounded, dark green leaves and, in summer, slender, upright stems bearing loose panicles of pendent, bell-shaped, purple flowers with recurved petals.

Thalictrum delavayi 'Hewitt's Double' (Chinese Meadow Rue)

An erect, clump-forming perennial with slender, purple-flushed stems, deeply-divided green leaves, and panicles of small, double, pale purple flowers in midsummer to early autumn. Height 1.5m (5ft), Spread 50cm (1.5ft).

Tiarella 'Pink Skyrocket' (Foam Flower)

A clump-forming, deciduous to semi-evergreen perennial bearing rosettes of mid- to dark green leaves with maroon-marked central veins and upright racemes of fluffy, pink flowers in late spring and early summer.

Tiarella 'Spring Symphony' (Foam Flower)

A low-growing, creeping perennial which makes a good ground cover plant. It has deep green, palmate foliage and in spring it has slender stems that rise above the foliage with light pink, star-shaped foamy flowers on top.

Tiarella cordifolia (Foam Flower)

A herbaceous perennial with lobed basal leaves and short upright spikes of foamy flowers in late spring and early summer. Height & Sread 50cm (1.5ft).

Tricyrtis 'Blue Wonder' (Toad Lily)

A compact, clump-forming, perennial with mid- to dark green leaves &, from late summer into autumn, upright stems bearing clusters of star-shaped, blue-flushed, creamy-white flowers, heavily spotted purple or purple-blue.

Trillium erectum (Birthroot)

A vigorous, upright perennial with erect stems, each bearing a whorl of three pointed, mid-green leaves and, in spring, reddish-purple flowers, sometimes white or yellow, with spreading to slightly recurved petals.

Tulbaghia violacea 'Silver Lace' (Society Garlic)

A clump-forming perennial with garlic-scented, cream and grey-green variegated leaves and erect stems bearing large clusters of fragrant, pale purple flowers from midsummer to early autumn. Height & Spread 50cm (1.5ft).

Verbascum chaixii 'Album' (White Nettle-Leaved Mullein)

A clump-forming perennial with grey hairy leaves and white flowers with purple centres, in late summer. Height 1m (3ft), Spread 50cm (1.5ft).

Verbascum olympicum (Olympian Mullein)

A tall, rosette-forming biennial or short-lived, evergreen perennial with large, woolly, silver-grey leaves and erect, woolly, silver-grey stems bearing bright golden- yellow flowers in late summer.

Verbascum x hybrida 'Southern Charm'

A perennial forming long spikes of flowers in a range of bright colours including apricot, pink, cream and yellow from late spring into early summer. Height & Spread 75cm (2.5ft).

Verbena 'Seabrook's Lavender' (Vervain)

A vigorous, tender, mound-forming to spreading, semi-evergreen perennial with ovate to oblong, toothed, wrinkled, dark green leaves and dense clusters of small, lavender to lavender-pink flowers in summer.

Verbena bonariensis

A herbaceous perennial that produces heads of bright purple flowers from June until October. Particularly effective if grown in a mass. Height 2.5m (8ft), Spread 50cm (1.5ft).

Verbena bonariensis 'Royal Dreams'

A compact, open clump-forming, deciduous perennial with stiff, erect, branching stems bearing dense clusters of small, mauve-pink flowers throughout summer into autumn. Height & Spread 60cm (2ft).

Veronica gentianoides (Gentian Speedwell)

A mat-forming, deciduous to semi-evergreen perennial with rosettes of broadly lance-shaped, sometimes scalloped, dark green leaves and erect racemes of cup-shaped, pale blue flowers in early summer.

Veronicastrum virginicum 'Fascination' (Culver's Root)

A clump forming, herbaceous perennial with whorls of pointed, green leavs. Long, bent racemes of lavender blue flowers with red eyes appear in summer. Height 1.5m (5ft), Spread 50cm (1.5ft).

Veronicastrum virginicum 'Lavendelturm' (Culver's Root)

A clump forming, herbaceous perennial producing tall clumps of strong stems with whorled serrated leaves around the stem, topped with pale lavender flower spikes in summer. Height 1.5m (5ft), Spread 50cm (1.5ft).

Zantedeschia 'Picasso' (Arum Lily)

A semi-evergreen, herbaceous perennial grown in water or boggy conditions. Large, satiny purple-white spathes are held singly on tall stems above broad, glossy, spotted foliage. Height 1m (3ft), Spread 50cm (1.5ft).

Zantedeschia aethiopica 'Green Goddess' (Arum Lily)

A perennial suitable for ponds or bog gardens. It has white spathes, flushed green with yellow spadices held on tall stems above large dark-green leaves. Height 1m (3ft), Spread 50cm (1.5ft).