Plants
- Sweet ChestnutCastanea sativa
- Sweet Chestnut 'Asplenifolia'Castanea sativa Asplenifolia
- Sweet CicelyMyrrhis odorata
- Sweet CornZea mays
- Sweet Corn 'Northern Extra Sweet'Zea mays 'Northern Extra Sweet'
- Sweet Dumpling Squash
- Sweet GumLiquidambar styraciflua 'Palo Alto'
- Sweet MarjoramMajorana majorana
- Sweet Mint
- Sweet PeaLathyrus odoratus
- Sweet Pea. Everlasting PeaLathyrus (General)
- Sweet PepperCapsicum annuum
- Sweet PepperbushClethra alnifolia
- sweet potato
- Sweet SultanCentaurea moschata
- Sweet VioletViola odorata
- Sweet William, 'Sooty'Dianthus barbatus 'Sooty'
- Sweet WoodruffGalium odoratum
- Sweet-flag Acorus calamus
- Sycamore Acer pseudoplatanus
- Sycamore (Variety) 'Brilliantissimum'Acer pseudoplatanus Brilliantissimum
- SymphoricarposSymphoricarpos
- SymphytumSymphytum caucasicum
- Symphytum 'Hidcote Blue'Symphytum grandiflorum 'Hidcote Blue'
- Symphytum ibericum, Symphytum grandiflorumSymphytum ibericum, Symphytum grandiflorum
- Symphytum x uplandicumSymphytum x uplandicum
- Synadenium GrantiiSynadenium Grantii
- Syrian JuniperJuniperus drupacea
- Syringa 'Miss Canada'Syringa 'Miss Canada'
- Syringa vulgarisSyringa vulgaris
- Syringa vulgaris 'Firmament'Syringa vulgaris 'Firmament'
- Syringa vulgaris 'Mme Lemoine'Syringa vulgaris 'Mme Lemoine'
- Syringa vulgaris .Lilac