Plants
- Solanum tuberosum 'Toluca'Solanum tuberosum 'Toluca'
- Solanum tuberosum 'Vitelotte Noir'Solanum tuberosum 'Vitelotte Noir'
- Solidaster 'Lemore'Solidaster luteus 'Lemore'
- Solidaster hybridus 'Luteus'Solidaster hybridus 'Luteus'
- Sorbaria var. angustifoliaSorbaria tomentosa var. angustifolia
- Sorbus hupehensis, Sorbus glabrescensSorbus hupehensis, Sorbus glabrescens
- sorbus koehneanasorbus koehneana
- Southern PolypodyPolypodium cambricum
- Southern Polypody 'Caren Lane'Polypodium cambricum 'Caren Lane'
- Sowbread, CyclamenCyclamen cilicium (Pink Form)
- Spanish GorseGenista hispanica
- Spear ThistleCirsium vulgare
- Spear Thistle, Queen Anne's thistleCirsium canum
- Speedwell 'Shirley Blue'Veronica 'Shirley Blue'
- Spiky FescueFestuca gautieri
- spilanthes acmellaspilanthes acmella
- Spilanthes oleraceaSpilanthes oleracea
- Spinacia oleracea 'Reddy'Spinacia oleracea 'Reddy'
- Spindle tree 'Red Cascade'Euonymus europaeus 'Red Cascade'
- Spiraea 'Pink Ice'Spiraea x vanhouttei 'Pink Ice'
- Spiraea 'Shirobana'Spiraea japonica 'Shirobana'
- Spiraea nipponica 'Snowmound'Spiraea nipponica 'Snowmound'
- Spring Snowflake,Var vagneri.Leucojum vernum var vagneri.
- Springbeauty Claytonia perfoliata
- Spurge 'Betten'Euphorbia x gayeri 'Betten'
- Spurge 'Blue Hills'Euphorbia characias subsp. characias 'Blue Hills'
- Stachys 'Superba'Stachys macrantha 'Superba'
- Stachys byzantina 'Cotton ball'Stachys byzantina 'Cotton ball'
- Stachys grandiflora 'Superba',Stachys grandiflora 'Superba',
- Stachys Grandiflora albaStachys Grandiflora alba
- Stachys sieboldii syn. affinisStachys sieboldii syn. affinis
- Stachyurus praecoxStachyurus praecox
- Star-of-BethlehemOrnithogalum (General)
- Stephanandra tanakaeStephanandra tanakae
- StewartiaStewartia pseudocamellia