• Planting in September or March is ideal, but most container grown plants can be planted any time the soil is not frozen or waterlogged
• Avoid planting slightly tender plants in autumn – wait until March
• Ensure the area to be planted is free of perennial weeds before planting
• If the area has not been planted before, dig in or rotovate 1 to 2 bucketfuls per sq m of well-rotted farmyard manure or garden compost
• After planting, apply a 5-7cm (2-3in) layer of the above organic matter to the whole border, keeping the crowns of plants clear to avoid risk of rotting

An indication of flower colour is given as a broad grouping  and is intended as a guide only:-

Key:
a White or cream flowers
b Yellow or orange flowers
c Red or pink flowers
d Blue or mauve flowers

AGM  Denotes plants which have received the Society's Award of Garden Merit.

May

Aurinia saxatilis (syn. Alyssum saxatile) AGM (b)
Anchusa azurea ‘Loddon Royalist’ (d)
Bergenia cordifolia (c)
Brunnera macrophylla AGM (d)
Crambe cordifolia AGM (a)
Lamprocapnos spectabilis AGM (c)
Doronicum ‘Little Leo’ (b)
Eremurus stenophyllus AGM , E. robustus AGM (a)
Euphorbia griffithii ‘Dixter’ AGM, E. myrsinites AGM, E. characias subsp. wulfenii (b)
Geranium macrorrhizum ‘Ingwersens Variety' AGM, G. renardii AGM (c)
Geum ‘Mrs J. Bradshaw’ AGM (c), G. ‘Lady Stratheden’ AGM (b)
Lamium maculatum ‘White Nancy’ (a), L. ‘Beacon Silver’ (c)
Libertia chilensis Formosa Group (a)
Polygonatum × hybridum AGM (a)
Pulmonaria saccharata ‘Mrs Moon’ (c)
Ranunculus aconitifolius ‘Flore Pleno’ AGM (a)
Saponaria ocymoides AGM (c)
Tiarella cordifolia AGM (a)
Trollius chinensis ‘Golden Queen’ AGM, T. × cultorum ‘Orange Princess’ AGM (b)
Veronica austriaca subsp. teucrium ‘Royal Blue’ AGM (d), V. gentianoides (d)

June

Acanthus spinosus (d)
Achillea ptarmica (The Pearly Group) ‘The Pearl’ (a), A. ‘Coronation Gold’ (b)
Ajuga reptans ‘Burgundy Glow’, A. ‘Multicolor’ (d)
Alchemilla mollis AGM (b)
Alstroemeria aurea (A. aurantiaca) (b)
Anthemis tinctoria ‘E.C. Buxton’ (a)
Astrantia major (a/c), A. maxima AGM (c)
Campanula portenschlagiana AGM (d), C. poscharskyana 'Stella' AGM (d), C. persicifolia (a/d), C. latifolia ‘Alba’ (a), C. lactiflora ‘Prichard’s Variety' AGM (d)
Centaurea dealbata ‘Steenbergii’ (c)
Centranthus ruber var. coccineus (c)
Coreopsis grandiflora ‘Early Sunrise’ AGM (b)
Delphinium ‘Galahad’ (a), D. King Arthur Group (d)
Dianthus (Allwoodii Group) ‘Doris’ AGM (c), D. ‘Mrs Sinkins’ (a)
Dictamnus albus var. purpureus AGM (c)
Echinops ritro AGM (d)
Erigeron 'Dunkelste Aller' (d)
Geranium × oxonianum ‘Wargrave Pink’ (c), G. ‘Johnson’s Blue’ (d), G. sanguineum (c), G. sanguineum ‘Album’ AGM (a)
Heuchera villosa ‘Palace Purple’ (a), H. cylindrica ‘Greenfinch’ (a), H. ‘Red Spangles’ (c)
Iris ‘Party Dress’ (c)
Leucanthemum × superbum ‘Wirral Supreme’ AGM (a)
Lysimachia punctata (b)
Oenothera macrocarpa (syn. O. missouriensis) AGM (b)
Paeonia lactiflora ‘ Duchess de Nemours’ AGM (a), P. lactiflora ‘Sarah Bernhardt’ AGM (c)
Papaver ‘Perry’s White’ (a), P. ‘Aglaja’ AGM (c)
Penstemon barbatus ‘Coccineus’ (c)
Potentilla ‘Gibson’s Scarlet’ AGM (c), P. nepalensis ‘Miss Willmott’ (c)
Rheum palmatum ‘Rubrum’ (c)
Salvia × sylvestris ‘Mainacht’ AGM (d), S. nemorosa ‘Caradonna’
Sisyrinchium striatum (b)
Stachys byzantina (c)
Thalictrum aquilegiifolium (d)
Tradescantia (Andersoniana Group) 'Osprey' (d) and other cultivars
Verbascum (Cotswold Group) ‘Cotswold Beauty’ AGM, V. (Cotswold Group) ‘Gainsborough’ AGM (b)
Veronica austriaca subsp. teucrium ‘Crater Lake Blue’ AGM (d)

July

Aconitum ‘Bressingham Spire’ AGM (d)
Agapanthus campanulatus var. albidus (a)
Catananche caerulea ‘Major’ AGM (d), C. caerulea ‘Alba’ (a)
Crocosmia ‘Lucifer’ AGM (c)
Dictamnus albus var. purpureus AGM (c)
Echinacea purpurea (c)
Eryngium × oliveranum AGM, E. variifolium (d)
Galega × hartlandii ‘Lady Wilson’ AGM (d), G. × hartlandii ‘Alba’ AGM (a)
Gypsophila paniculata ‘Bristol Fairy’ (a)
Helenium ‘Butterpat’ AGM (b)
Helianthus ‘Loddon Gold’ AGM (b)
Heliopsis helianthoides var. scabra ‘Goldgefieder’  (b)
Hemerocallis ‘Golden Chimes’ (b), H. ‘Pink Damask’ (c), H. ‘Stafford’ AGM (c)
Hosta e.g. H. ‘Royal Standard’ AGM (d)
Hylotelephium spectabile (Brilliant Group) ‘Brilliant’ (syn. Sedum spectabile (Brilliant Group) ‘Brilliant’) AGM (c), H. ‘Ruby Glow’ (syn. Sedum ‘Ruby Glow’) AGM (c)
Iris ‘Perry’s Blue’ (d)
Kniphofia ‘Royal Standard’ AGM (b)
Liatris spicata ‘Kobold’ (d)
Ligularia przewalskii, L. dentata ‘Desdemona’ (b)
Limonium latifolium (d)
Lychnis chalcedonica AGM (c)
Lysimachia punctata (b)
Lythrum salicaria ‘Feuerkerze’ (syn. ‘Firecandle’) AGM (c)
Monarda ‘Croftway Pink’, M. ‘Cambridge Scarlet’ (c)
Oenothera fruticosa ‘Fyrverkeri’ (syn. ‘Fireworks’) AGM (b)
Physostegia virginiana ‘Summer Snow’ AGM (a)
Platycodon grandiflorus 'Mariesii' AGM (d)
Prunella grandiflora ‘Loveliness’ (c)
Rudbeckia fulgida var. sullivantii 'Goldsturm'  (b)
Salvia sclarea var. turkestanica 'Vatican Pink' (d)
Scabiosa caucasica ‘Miss Willmott’ AGM (a), S. ‘Clive Greaves’ AGM(d)
Sedum ‘Coral Carpet’
Sidalcea ‘Croftway Red’, S. ‘Rose Queen’ (c)
Solidago ‘Goldenmosa’ AGM (b)
Stokesia ‘Blue Star’ (d)
Veronicastrum virginicum ‘Album’ AGM (a)

August

Actaea cordifolia (a/c)
Anaphalis triplinervis AGM (a) 
Anemone × hybrida cultivars (a/c)
Ceratostigma plumbaginoides AGM (d)
Ophiopogon planiscapus ‘Nigrescens’ AGM (c)
Persicaria affinis, P. affinis ‘Superba’ AGM, P. affinis ‘Darjeeling Red’ AGM (c)
Symphyotrichum novae-angliae 'Andenken an Alma Pötschke'
Zauschneria californica ‘Dublin’ AGM (c)

September

Aster thomsonii ‘Nanus’ (d)
Aster × frikartii ‘Mönch’ AGM (d)
Hesperantha coccinea 'Major' AGM (c)
Hylotelephium (Herbstfreude Group) 'Herbstfreude'  (syn. Sedum (Herbstfreude Group) 'Herbstfreude') AGM (c)
Liriope muscari AGM (d)
Nerine bowdenii AGM (c)

Some herbaceous perennials for dry shade

Ajuga reptans ‘Variegata’ (d), A. reptans ‘Multicolor’ (d), A. reptans f. albiflora 'Alba' (a)
Alchemilla mollis AGM (b)
Bergenia cordifolia ‘Purpurea’ AGM, B. 'Ballawley' clonal  (c)
Brunnera macrophylla AGM (d)
Lamium maculatum (c)
Liriope muscari AGM (d)
Pulmonaria angustifolia AGM, P. officinalis, P. saccharata Argentea Group (c)
Salvia nemorosa ‘Ostfriesland’ AGM (c/d)
Salvia × sylvestris ‘Mainacht’ AGM (d)
 

Some herbaceous perennials for moist shade

Alchemilla mollis AGM (c)
Aruncus dioicus AGM (a)
Astilbe 'Deutschland' (japonica hybrid) (a), A. (× arendsii) ‘Fanal’ AGM
Caltha palustris ‘Flore Pleno’ (b)
Darmera peltata AGM (c)
Filipendula ulmaria ‘Aurea’ (a)
Gunnera manicata (a)
Helleborus niger, H. foetidus AGM (a)
Hosta ‘Royal Standard’ AGM (d)
Ligularia przewalskii (b), L. ‘Gregynog Gold’ AGM (b)
Lythrum salicaria ‘The Beacon’ (c)
Monarda ‘Cambridge Scarlet’ AGM (c), M. ‘Croftway Pink’ AGM (c)
Persicaria affinis ‘Darjeeling Red’ AGM (c)
Trollius × cultorum ‘Alabaster’ (a), Trollius × cultorum 'Goldquelle'  AGM (b), T. cultorum

Some herbaceous perennials for dry sites in full sun

Acanthus spinosus (d)
Achillea (a/b)
Agapanthus (milder areas) (d) or (a)
Anaphalis triplinervis AGM (a)
Aurinia saxatilis AGM (b)
Bergenia cordifolia (c)
Catananche caerulea (d)
Centaurea dealbata (c)
Crocosmia ‘Lucifer’ AGM(c)
Dianthus ‘Memories’ (a)
Euphorbia myrsinites AGM, E. characias subsp. wulfenii (b)
Geranium ‘Johnson’s Blue’ (d), G. × oxonianum ‘Wargrave Pink’(c), G. Rozanne = 'Gerwat' AGM
Hylotelephium spectabile (syn. Sedum spectabile) (c), H. (Herbstfreude Group) 'Herbstfreude'  (syn. Sedum (Herbstfreude Group) 'Herbstfreude') AGM (c), H. ‘Ruby Glow’ (syn. Sedum ‘Ruby Glow’) AGM (c)
Iris germanica cultivars (b/d)
Kniphofia cultivars (c)
Oenothera fruticosa 'Fyrverkeri’ (b)
Penstemon ‘Schoenholzeri’ (syn. ‘Firebird’) AGM (c), P. ‘Evelyn’ AGM (d)
Potentilla ‘Gibson’s Scarlet’ AGM (c)
Solidago (b)
Stachys byzantina (d)
Viola ‘Huntercombe Purple’ AGM (d)