| Rhamnus frangula 'Asplenifolia' |
| Rhaphiolepis x delacourii 'Spring Song' |
| Rhaphiolepis umbellata (AGM) |
| Rhododendron 'Blue Diamond' |
| Rhododendron 'Doc' (AGM) |
| Rhododendron 'Dopey' (AGM) |
| Rhododendron 'Dusty Miller' |
| Rhododendron 'Grumpy' |
| Rhododendron 'Hoppy' |
| Rhododendron impeditum (AGM) |
| Rhododendron 'Lord Roberts' (AGM) |
| Rhododendron 'Percy Wiseman' |
| Rhododendron 'Pink Cherub' (AGM) |
| Rhododendron ponticum 'Variegatum' |
| Rhododendron 'Praecox' (AGM) |
| Rhododendron 'Purple Splendour' (AGM) |
| Rhododendron russatum (AGM) |
| Rhododendron 'Sapphire' (AGM) |
| Rhododendron 'Scintillation' |
| Rhododendron 'Silver Sixpence' (AGM) |
| Rhododendron 'Sneezy' |
| Rhododendron 'Snipe' (AGM) |
| Rhododendron 'Surrey Heath' (AGM) |
| Rhododendron 'Titian Beauty' (AGM) |
| Rhododendron 'Venetian Chimes' |
| Rhododendron 'Windlesham Scarlet' (AGM) |
| Rhus typhina |
| Rhus typhina 'Dissecta' (AGM) |
| Ribes alpinum 'Aureum' |
| Ribes x gordonianum |
| Ribes laurifolium |
| Ribes odoratum (syn aureum) |
| Ribes sanguineum 'Brocklebankii' |
| Ribes sanguineum 'King Edward VII' |
| Ribes sanguineum 'Pulborough Scarlet' (AGM) |
| Ribes sanguineum 'Pulborough Scarlet Variegated' |
| Ribes sanguineum 'White Icicle' |
| Ribes viburnifolium |
| Robinia hispida 'Rosea' |
| Robinia pseudoacacia 'Lace Lady'\n(Standard) |
| Romneya coulteri (AGM) |
| Rosmarinus officinalis |
| Rosmarinus officinalis albiflorus |
| Rosmarinus officinalis 'Beneden Blue' |
| Rosmarinus officinalis 'McConnell's Blue' |
| Rosmarinus officinalis 'Miss Jessop's Upright' (AGM) |
| Rosmarinus officinalis Prostratus (AGM) |
| Rosmarinus officinalis 'Roseus' |
| Rosmarinus officinalis 'Severn Sea' (AGM) |
| Rosmarinus officinalis 'Sissinghurst Blue' (AGM) |
| Rosmarinus officinalis 'Tuscan Blue' |
| Rubus 'Benenden' (AGM) |
| Rubus biflorus |
| Rubus cockburnianus (AGM) |
| Rubus cockburnianus 'Golden Vale' |
| Rubus rosifolius 'Coronarius' |
| Rubus spectabilis 'Olympic Double' |
| Rubus thibetanus (AGM) |
| Ruscus aculeatus |
| Ruta graveolens 'Jackman's Blue' (AGM) |