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 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 Rose' (Yarrow)

A compact, mound-forming, deciduous to semi-evergreen perennial with finely-divided grey-green leaves and, from summer into autumn, erect stems bearing flattened clusters of tiny, pink flowers turning pale pink with age.

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.

Achillea millefolium 'Paprika' (Yarrow)

An upright, clump-forming, herbaceous perennial with finely-divided, dark green leaves and, in summer, erect stems bearing flat clusters of orange-red flowers with yellow centres, that fade with age.

Achillea millefolium 'The Beacon' (Yarrow)

An erect herbaceous perennial with fern-like, dark green leaves and large, flat heads of dark red flowers with yellow centres. Height & Spread 60cm (2ft).

Actaea simplex 'Brunette' (Bugbane)

A clump-forming, herbaceous perennial with dark purple-bronze foliage and fragrant, pink-flushed white flowers on dark wiry stems in late summer to early autumn. Height 1.5m (5ft), Spread 50cm (1.5ft).

Agapanthus 'Brilliant Blue' (African Lily)

A compact, clump-forming, half-hardy, semi-evergreen perennial bearing dark green leaves and sturdy, erect stems bearing rounded umbels of trumpet-shaped, deep blue flowers in summer. Height & Spread 50cm (1.5ft).

Agapanthus 'Charlotte' (African Lily)

A compact, clump-forming, half-hardy perennial with strap-shaped, mid-green leaves, &, in summer, tall stems bearing rounded umbels of star-shaped, blue flowers with a dark violet-blue stripe down the centre of each petal.

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 'Dr. Brouwer' (African Lily)

A semi-evergreen herbaceous perennial with dark green, strap-shaped leaves forming at its base. In late summer it bears large, spherical heads of tubular pale violet-blue and dark blue flowers on upright stems.

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 '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 '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).

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.

Alcea 'Apple Blossom' (Hollyhock)

A vigorous, upright biennial or short-lived perennial with rounded, lobed, veined, rough, mid- to grey-green leaves and long, erect racemes of double, pink flowers in summer. Height 2m (6ft), Spread 50cm (1.5ft).

Alcea rosea 'Chater's Double Salmon Pink' (Hollyhock)

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

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).

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

A vigorous, upright biennial or short-lived perennial with lobed, rounded, rough, mid- to dark green leaves and large, double, yellow 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 'Ambassador' (Giant Allium)

A bulbous perennial with glossy, strap-shaped, bright green leaves and, from late spring into summer, sturdy, erect stems bearing large, dense, rounded umbels of dark purple flowers. Height 1.2m (4ft), Spread 50cm (1.5ft).

Allium 'Globemaster'

A bulbous, deciduous perennial with strap-shaped, grey-green leaves and globular clusters of starry violet-purple flowers on tall, erect stems in summer. Height 1.5m (5ft), Spread 50cm (1.5ft).

Allium 'Lucy Ball'

A bulbous perennial with strap-shaped green leaves and spherical heads of purple flowers on tall upright stems in early summer. Height 1m (3ft), Spread 30cm (1ft).

Allium cristophii (Star Of Persia)

A bulbous perennial, with strap-shaped, grey-green leaves. Star-shaped, rosy-violet flowers are borne in spherical heads in early summer which are followed by attractive seed-heads. Height & Spread 60cm (2ft).

Allium hollandicum 'Purple Sensation'

A bulbous perennial, with strap-shaped, grey-green leaves and small, vivid rosy-purple flowers, in crowded spherical umbels. Height 1m (3ft), Spread 60cm (2ft).

Allium roseum (Rosy Garlic)

A low-growing bulbous perennial with strap-shaped leaves. In late spring or early summer, it bears loose clusters of dainty pink flowers. Height 30cm (1ft), Spread 50cm (1.5ft).

Allium stipitatum 'Mount Everest'

A clump-forming, bulbous perennial with glossy, strap-shaped, green leaves and, in summer, sturdy, erect stems bearing dense, rounded umbels of star-shaped, white flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

Allium stipitatum 'Violet Beauty' (Persian Shallot)

A clump-forming, bulbous perennial with glossy, strap-shaped, mid-green leaves and, in summer, sturdy, erect stems bearing dense, dome-shaped umbels of star-shaped, violet flowers in summer.

Alstroemeria 'Summer Break' (Peruvian Lily)

An upright, clump-forming, tuberous perennial with dark green leaves and, from early summer into autumn, clusters of funnel-shaped, white-marked bright pink flowers with brown-flecked, yellow-flushed inner petals.

Alstroemeria 'Summer Sky' (Peruvian Lily)

An upright, clump-forming, tuberous perennial with narrowly lance-shaped, dark green leaves and, from early summer into autumn, clusters of funnel-shaped, white flowers with brown-flecked, yellow-marked upper petals.

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 'Ruffled Swan' (Japanese Anemone)

An erect, woody-based perennial with oval, palmate, toothed, mid- to dark green leaves and, from early summer to early autumn, dark erect, branching stems bearing semi-double, white flowers, purple on the reverse.

Anemone hupehensis var. japonica 'Bressingham Glow'

An erect, clump-forming, herbaceous perennial with deeply divided, mid-green basal leaves and, from late summer to early autumn, upright, wiry stems bearing semi-double, deep rose-pink flowers with yellow centres.

Anemone hupehensis var. japonica 'Prince Heinrich'

A herbaceous perennial with attractively divided green leaves. It bears semi-double rose-pink flowers in summer. Height & Spread 1m (3ft).

Anemone x hybrida 'Andrea Atkinson' (Japanese Anemone)

A herbaceous perennial forming clumps of large, dark, divided, vine-line leaves and pure white flowers with contrasting orange-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).

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 'Blue Star' (Columbine)

An upright, clump-forming, herbaceous perennial with blue-green leaves and upright, wiry stems bearing nodding, spurred, pale violet-blue and white flowers in late spring and early summer. Height & Spread 50cm (1.5ft).

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 'Earlybird Purple Blue' (Columbine)

A compact, mound-forming, deciduous perennial with mid-green leaves and, from late spring into summer, slender, upright stems bearing spurred flowers with purple to purple-pink outer sepals and lilac-blue petals.

Aquilegia 'Earlybird Red Yellow'

A compact, clump-forming, herbaceous perennial with mid- to dark green leaves and slender, upright stems bearing small, bright red and pale yellow flowers from late spring into early summer. Height & 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 'William Guiness' (Columbine)

An upright herbaceous perennial with divided foliage and, in spring and summer, striking flowers with deep maroon-purple sepals and white petals with deep purple spurs. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Aquilegia vulgaris var. stellata 'Nora Barlow' (Columbine)

An upright herbaceous perennial, with nodding, spurless, double flowers and divided, dark-green leaves. The flower heads are made of many narrow, variagated pale/dark-pink/pale-green petals.

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).

Armeria maritima 'Splendens' (Thrift)

A compact, dense, tufted, evergreen perennial with stiff, grass-like dark green leaves and slender, erect, stems bearing compact, ruonded clusters of reddish-pink flowers from mid-spring into summer.

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 'Dandy' (Michaelmas Daisy)

A dwarf, bushy, clump-forming perennial with slender, branched stems bearing lance-shaped, dark-green leaves and a profusion of intense, violet flowers with yellow centres in late summer to autumn.

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 'Astary Rose'

A clump-forming, dwarf herbaceous perennial with glossy, toothed, dark green leaves. Produces branching, conical plumes of deep rose pink flowers in midsummer. Height & Spread 50cm (1.5ft).

Astilbe 'Astary White'

A compact, mound-forming, deciduous perennial with ovate, toothed, deeply-divided, dark green leaves and erect stems bearing branched, triangular panicles of white flowers in summer. Height & Spread 30cm (1ft).

Astilbe 'Deutschland'

An upright, clump-forming perennial with feathery green foliage, which unfurls in spring, followed in late summer with plumes of white flowers. Height 1m (3ft), Spread 60cm (2ft).

Astilbe chinensis (Chinese Astilbe)

A vigorous, upright, clump-forming, deciduous perennial with toothed, softly hairy, dark green leaves divided into three leaflets and upright, dense panicles of pale pink flowers in late summer. Height & Spread 60cm (2ft).

Astilbe x arendsii 'Bressingham Beauty'

A tall, spreading, deciduous perennial with bronze-flushed, mid-green leaves divided into three ovate to lance-shaped leaflets and panicles of bright pink flowers in midsummer. Height 1m (3ft), Spread 60cm (2ft).

Astrantia 'Roma' (Masterwort)

A clump-forming, deciduous perennial with deeply-divided, mid-green leaves and, from early summer to early autumn, erect, wiry, branching stems bearing umbels of rose-pink flowers surrounded by green-flushed, pink bracts.

Astrantia major 'Star of Billion' (Masterwort)

A clump-forming, herbaceous perennial with divided, mid-green leaves & branching stems bearing umbels of large white flowers with conspicuous green-tipped, white bracts in summer. Height 75cm (2.5ft), 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.

Bergenia 'Bressingham Ruby' (Elephant's Ears)

A clump-forming evergreen perennial with large leaves that turn dark-red in cold weather. Rose-red flowers on red stems in spring. Height 30cm (1ft), Spread 50cm (1.5ft).

Bergenia cordifolia 'Purpurea' (Elephant's Ears)

A clump-forming, evergreen perennial with thick, rounded to heart-shaped, dark green leaves, flushed purple in winter. Sturdy, upright, red stems bear cymes of bell-shaped, magenta flowers in spring.

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.

Brunnera macrophylla (Siberian Bugloss)

A clump-forming herbaceous perennial with large heart-shaped, long stalked-leaves and broad sprays of small, clear blue flowers. Height & Spread 50cm (1.5ft).

Campanula 'Kent Belle' (Bellflower)

A herbaceous perennial that bears vivid violet-blue, nodding, bell-shaped flowers on leafy stems in summer and early autumn. Height 1.5m (5ft), Spread 75cm (2.5ft).

Campanula carpatica 'Blue Clips' (Tussock Bellflower)

A small, spreading, mound-forming perennial with light green, heart-shaped leaves and purple-blue flowers from late spring to early autumn. Height & Spread 30cm (1ft).

Campanula poscharskyana (Trailing Bellflower)

A compact, mound-forming to spreading, deciduous perennial with rounded to ovate, toothed, mid-green leaves and panicles of star-shaped, violet-blue flowers from summer into autumn. Height 20cm (8in), Spread 1m (3ft).

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).

Cerastium tomentosum (Snow-in-Summer)

A vigorous, mat-forming, deciduous perennial with linear, white-hairy, silvery grey-green leaves and, in late spring and summer, star-shaped, white flowers with notched petals. Height 10cm (4in), Spread 1.5m (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).

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 '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).

Cynara cardunculus (Globe Artichoke)

A perennial with silvery-grey, thistle-like foliage and tall flower stems which are topped by fat thistle-like buds which resemble small globe artichokes in summer. Height 2.5m (8ft), Spread 1.5m (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 bushy, clump-forming, tuberous perennial with toothed, pinnate, purple- to black-flushed, dark green leaves and, in summer, semi-double brilliant red flowers. Height 1m (3ft), Spread 50cm (1.5ft).

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 'Catherine Deneuve'

A bushy, clump-forming, tuberous perennial with toothed, pinnate, purple- to bronze-flushed, dark green leaves and, in summer and autumn, upright stems bearing single, orange flowers with orange-red centres.

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 'Engelhardt's Matador'

An upright, bushy, clump-forming, tuberous perennial with pinnate, toothed, dark green-bronze leaves and, in summer and autumn, strong stems bearing decorative, purplish-pink flowers. Height 1m (3ft), Spread 75cm (2.5ft).

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 '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 '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 '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 '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 'Magic Fountain Mix'

A compact, upright, clump-forming, herbaceous perennial with deeply lobed, dark green leaves and, in summer, dense, erect racemes of bowl-shaped, semi-double flowers in shades of blue, pink, purple, or white.

Delphinium 'Magic Fountains Sky Blue'

An upright, clump-forming perennial with green divided foliage and in summer, bears sturdy spires of blue flowers. Very attractive to bees. Height 1m (3ft), Spread 60cm (2ft).

Delphinium 'Pacific Giant Mix'

An upright, herbaceous perennial with divided, dark-green foliage. From late spring until mid summer it bears erect racemes of purple, blue, lavender or white flowers. Height 2m (6ft), Spread 1m (3ft).

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).

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 purpurea 'Dalmatian Cream' (Foxglove)

A rosette-forming, hairy biennial or short-lived perennial with dark green leaves and, in early summer, tall, upright spikes of cream flowers with purple-speckled throats. Height 60cm (2ft), Spread 50cm (1.5ft).

Digitalis purpurea 'Excelsior Hybrid' (Foxglove)

A biennial plant, forming a basal clump of leaves then tall, upright spikes of white, yellow, pink or purple, bell-shaped flowers. Height 1.5ft (5ft), Spread 50cm (1.5ft).

Echinacea 'Papallo Classic Gold' (Coneflower)

A compact, upright, clump-forming, deciduous perennial with narrowly ovate to lance-shaped, rough-hairy, dark green leaves and golden yellow flowers throughout summer. Height 60cm (2ft), Spread 50cm (1.5ft).

Echinacea 'Papallo Power Coral Orange' (Coneflower)

A compact, upright, clump-forming, deciduous perennial with rough-hairy, dark green leaves and, throughout summer, coral-pink to orange flowers, bright pink at the petal base. Height 60cm (2ft), Spread 50cm (1.5ft).

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).

Echinops sphaerocephalus 'Arctic Glow' (Globe Thistle)

An erect, clump-forming, architectural perennial with spiny, deeply-divided, grey-green leaves, white beneath, and rounded, thistle-like, lilac-white flowerheads in summer. Height 1.5m (5ft), 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).

Erigeron 'Pink Jewel' (Fleabane)

A clump-forming perennial with lance-shaped, grey-green leaves and abundant numbers of single, yellow-centred, bright pink flowers in summer. Height 60cm (2ft), Spread 50cm (1.5ft).

Erigeron glaucus 'Sea Breeze' (Beach Aster)

A mound-forming, evergreen perennial with thick, often waxy or hairy, oval to spoon-shaped, grey-green leaves and, throughout summer, semi-double, daisy-like, lilac-pink flowers with yellow centres.

Erigeron karvinskianus (Mexican Flebane)

A mat- or mound-forming, deciduous to semi-evergreen perennial with hairy, dark green leaves and, in summer, daisy-like, white flowers turning pink to purple-pink with age. Height 30cm (1ft), Spread 1m (3ft).

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 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).

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. characias 'Humpty Dumpty'

A compact evergreen perennial with grey-green linear foliage and clusters of acid-green flowers in spring. Height & Spread 60cm (2ft).

Euphorbia myrsinites (Broad-Leaved Glaucous Spurge)

An evergreen perennial with trailing, leafy stems bearing spirally arranged, succulent, blue- to grey-green leaves and bright yellow-green flowers from late spring to midsummer. Height 10cm (4in), Spread 30cm (1ft).

Euphorbia palustris (Marsh Spurge)

A clump-forming perennial with upright stems clothed with narrow mid-green leaves that may become orange-tinted in autumn. In late spring, it bears terminal clusters of greenish yellow flowers. Height & Spread 1m (3ft).

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.

Euphorbia x martinii (Martin's Spurge)

An upright, clump-forming, evergreen sub-shrub with red-flushed stems bearing dark grey-green leaves, often flushed purple when young, and, from spring to midsummer, tiny purple flowers surrounded by yellow-green bracts.

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 '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 'Blushing Turtle' (Cranesbill)

A vigorous, upright to rounded, spreading, herbaceous perennial with deeply lobed, dark green leaves and, from summer into autumn, pink flowers with darker pink veins. Height 60cm (2ft), Spread 1m (3ft).

Geranium 'Johnson's Blue'

A vigorous, clump-forming perennial with lobed leaves and long-stems bearing rounded, dark-veined, lavender-blue flowers throughout summer. Height 50cm (1.5ft), 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 'Ingwersen's Variety'

A semi-evergreen perennial, with rounded, pale green aromatic leaves and soft lilac-pink flowers in summer. Height & Spread 50cm (1.5ft).

Geranium pratense 'Mrs Kendall Clark' (Meadow Cranesbill)

A vigorous, mound-forming, herbaceous perennial forming a clump of serrated and lobed leaves and subtle pale-violet flowers flushed rose-pink. Height & Spread 1m (3ft).

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 sylvaticum 'Mayflower' (Wood Cranesbill)

A herbaceous perennial with a compact habit. Its green leaves are deeply divided with lobed segments. In spring and summer it bears violet-blue flowers with white centres. Height 75cm (2.5ft), Spread 50cm (1.5ft).

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 '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 '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 'Totally Tangerine' (Avens)

A vigorous, mound-forming, herbaceous perennial with pinnate, hairy, mid-green basal leaves and slender stems bearing semi-double, apricot to orange flowers from late spring into autumn. Height 1m (3ft), Spread 60cm (2ft).

Gypsophila cerastioides (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, white, trumpet shaped flowers.

Helenium 'Moerheim Beauty' (Sneezeweed)

An upright, clump-forming perennial with lance-shaped green leaves and large, dark-centred, copper-red flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

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).

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 '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 '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 '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 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 'Hopscotch' (Foamy Bells)

A mound-forming, semi-evergreen to evergreen perennial bearing lobed leaves in shades of bronze-red turning deep green in summer. Slender stems bear panicles tiny, bell-shaped, cream flowers from late spring into 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 'Twilight'

A clump-forming, herbaceous perennial bearing glossy, dark green leaves with wide, yellow margins. Racemes of funnel-shaped, lavender flowers bloom on slender stalks in summer. Height 60cm (2ft), 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 sieboldiana 'Big Daddy'

A clump-forming perennial with broad, heart-shaped, puckered leaves, and greyish-white flower spikes in summer. Height 60cm (2ft), 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 'Black Dragon' (Tall Bearded Iris)

A vigorous, clump-forming, perennial with upright, grey-green leaves and, in late spring and early summer, erect stems bearing large, ruffled flowers with dark purple standards and black-flushed, dark purple falls.

Iris 'Bold Print'

A clump-forming, rhizomatous perennial with narrow, sword-shaped, grey-green leaves and, in spring, upright stems bearing purple-edged, white flowers. Height & Spread 60cm (2ft).

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 '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 'Bees' Lemon' (Red Hot Poker)

A clump-forming, deciduous perennial with toothed, grass-like, mid-green leaves &, in late summer to early autumn, upright racemes of lemon-yellow flowers opening from green buds. 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 citrina (Yellow Red Hot Poker)

A clump-forming, evergreen perennial with upright to arching green leaves and, from late spring into summer, erect stems bearing bright green buds opening to tubular, yellow-green flowers turning yellow-orange with age.

Kniphofia uvaria 'Flamenco' (Red Hot Poker)

An evergreen perennial with strap-shaped leaves with yellow, orange or fiery red spikes of tubular flowers from early summer to early autumn. If sown early, will flower early autumn in its first year.

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.

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).

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 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).

Lupinus 'Chandelier' (Lupin)

A clump-forming, herbaceous perennial with palmate, mid-green leaves and tall, upright, terminal racemes of yellow flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

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 White' (Lupin)

A dwarf, clump-forming, herbaceous perennial with palmate, mid-green leaves and tall, upright, terminal racemes of white flowers from spring until 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 'Lupini Blue Shades' (Lupin)

A compact, upright, bushy, perennial with palmate, dark blue-green leaves and, in summer, erect racemes of deep blue, pea-like flowers. Height & Spread 30cm (1ft).

Lupinus 'Noble Maiden' (Lupin)

A clump-forming perennial with palmate, mid-green leaves and long, upright, terminal racemes of pure white flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

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 'Alba' (Garden Catmint)

A compact, bushy, clump-forming, herbaceous perennial with aromatic, toothed, grey-green leaves and loose spikes of whorled, two-lipped, tubular, white flowers throughout summer. Height 30cm (1ft), 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 '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 'Bowl of Beauty' (Peony)

A herbaceous perennial with dark green leaves on red stems and large, rose-pink double flowers with a creamy fringed centre in summer. Height 2.5m (8ft), Spread 1.5m (5ft).

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 '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 '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).

Paeonia suffruticosa 'Houki' (Tree Peony)

A clump-forming perennial shrub with divided, deep green leaves that turn bronze and purple in autumn. In late spring, it bears large, sweetly fragrant, double, ruby-red flowers with golden stamens.

Papaver orientale 'Brilliant' (Oriental Poppy)

An upright, clump-forming perennial with finely divided, dark to grey-green leaves and, from late spring to early summer, large, bright orange-red flowers with black central blotches. Height 1.2m (4ft), Spread 1m (3ft).

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 digitalis 'Husker Red'

An upright, bushy, semi-evergreen perennial with lance-shaped, maroon-flushed, dark green leaves and racemes of bell-shaped, pink-flushed, white flowers in summer. Height 1m (3ft), Spread 50cm (1.5ft).

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 'Franz Schubert'

A herbaceous perennial with erect stems of lance-shaped leaves and large panicles of fragrant, lilac flowers from mid-summer. Height 1m (3ft), Spread 30cm (1ft).

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.

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 fulgida 'Viette's Little Suzy' (Coneflower)

A compact, rhizomatous perennial with hairy green leaves & branching stems that carry flowers with deep-brown centres & warm-golden ray florets in mid- to late summer and early autumn. Height 1m (3ft), Spread 50cm (1.5ft).

Rudbeckia fulgida var. deamii (Deam's Coneflower)

A clump-forming, herbaceous perennial with ovate, rough, dark-green leaves and upright, leafy stems bearing daisy-like, golden-yellow flowers from late summer to mid-autumn. Height 75cm (2.5ft), 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).

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 '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 '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 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 'Rose Marvel' (Balkan Clary)

A compact, clump-forming, herbaceous perennial with aromatic, dark grey-green leaves and, from midsummer to early autumn, dense, erect racemes of deep rose-pink flowers with red-purple calyces. Height & Spread 30cm (1ft).

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.

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).

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 'Dark Magic'

A compact, upright, clump-forming, herbaceous perennial with fleshy, glossy, maroon to purple-black leaves and flattened clusters of dark pink flowers from late summer into autumn. Height 30cm (1ft), Spread 50cm (1.5ft).

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 'Herbstfreude' (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 telephium 'Desert Black' (Stonecrop)

A compact, upright, clump-forming, herbaceous perennial with fleshy, glossy, maroon to purple-black leaves and flattened clusters of rose-pink flowers from late summer into autumn. Height 50cm (1.5ft), Spread 60cm (2ft).

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.

Silene dioica 'Clifford Moor' (Red Campion)

A mound-forming, semi-evergreen perennial with variegated green and golden-yellow leaves and, in late spring and early summer, branching stems bearing clusters of pink flowers. Height 50cm (1.5ft), Spread 60cm (2ft).

Silene dioica 'Rollie's Favorite' (Red Campion)

A mound-forming, semi-evergreen perennial with ovate to oblong, dark green leaves and, in late spring and early summer, branching, semi-trailing stems bearing clusters of pink flowers with white eyes.

Silene schafta (Autumn Catchfly)

A clump-forming, semi-evergreen perennial with lance-shaped, bright green leaves and, from late summer into autumn, long-tubed, magenta flowers with notched petals. Height & Spread 30cm (1ft).

Thalictrum 'Nimbus Pink' (Meadow Rue)

A vigorous, erect, clump-forming, deciduous perennial with pinnate, blue-green leaves and dark stems bearing open panicles of tiny, pale pink flowers in summer. Height 75cm (2.5ft), Spread 50cm (1.5ft).

Thalictrum aquilegiifolium (Rue)

An erect, clump-forming, rhizomatous, herbaceous perennial with grey-green leaves and upright stems bearing large, flat-topped, panicles of fluffy, pale mauve to purple-pink flowers in summer.

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.

Tradescantia x andersoniana 'Bilberry Ice'

A tufted, clump-forming, evergreen perennial with branching stems bearing arching, slightly fleshy, dark green leaves and, from early summer into autumn, small clusters of 3-petalled, pale lavender-blue flowers.

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.

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.

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 'Lollipop'

A stiff, compact, open clump-forming, herbaceous perennial with erect, branching stems bearing lance-shaped, dark green leaves and branched clusters of small purple flowers from midsummer to early autumn.

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 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).