Sky Flower 'Golden Edge' Sky Flower Variegated
'Skybound' Sugar Maple 'Skylark' Blueblossom
'Skylark' Holly Grape 'Skylark' Oregon Grape
'Skyline' Thornless Honey Locust 'Skyrocket' Colorado Red Cedar
'Skyrocket' Rockcress Slash Pine
Slash Pine: elliottii 'Sleigh Bells' American Holly
Slender Blue Flag 'Slender Silhouette' Sweetgum
Slender Spike Rush 'Slim Jane' American Holly
Small leaf Mahogany Small Leaf Viburnum
Small Woodland Sunflower Small-Flowered Century Plant
Small-seeded Beargrass Smartweed: virginianum (spp.)
Smartweed: virginianum 'Compton's Form' Smartweed: virginianum 'Lance Corporal'
Smartweed: virginianum Variegated Smoke Tree, American
Smooth Azalea Smooth Blackhaw
Smooth Hydrangea (spp.) Smooth Hydrangea: arborescens (spp.)
Smooth Hydrangea: arborescens 'Annabelle' Smooth Hydrangea: arborescens 'Grandiflora'
Smooth Hydrangea: arborescens 'Incrediball®' Smooth Hydrangea: arborescens 'Invincibelle® Spirit'
Smooth Hydrangea: arborescens 'White Dome®' Smooth Serviceberry (spp.)
Smooth Serviceberry 'Lancifolia' Smooth Sumac
Smooth Witherod (spp.) Smooth Witherod 'Brandywine™'
Smooth Witherod 'Winterthur' Snakeberry
Snakewood, Bitter Snapdragon, Climbing 'Jewels'
Snapdragon, Creeping 'Jewels' Snapdragon, Island Bush
Snapdragon, Summer 'AngelMist™ Purple Stripe' Snapdragon, Trailing 'Jewels'
Snapdragon, Twining 'Jewels' Sneezeweed (spp.)
Sneezeweed, Common (spp.) Sneezeweed, Orange
'Snow Cushion' Bushy Aster Snow on the Mountain: marginata
'Snow Queen' Oakleaf Hydrangea Snow Shrimp Plant
Snow Trillium Snowball Cactus
'Snowball' Monterey Ceanothus Snowball, Wild
'Snowbank' False Chamomile: asteroides Snowbell, American
Snowberry, West Indian Snowberry: microphyllus
'Snowdrift' American Marigold 'Snowdrift' Fringed Bleeding Heart
Snowdrop Tree 'Snowflake' False Chamomile: asteroides
'Snowflake' Moss Phlox 'Snowflake' Oakleaf Hydrangea
Snowflake, Water Snowhill Hydrangea (spp.)
Snowhill Hydrangea 'Annabelle' Snowhill Hydrangea 'Grandiflora'
Snowhill Hydrangea 'Incrediball®' Snowhill Hydrangea 'Invincibelle® Spirit'
Snowhill Hydrangea 'White Dome®' Soap Tree Yucca
Soapberry, Florida Soapberry, Western
Soapberry, Wingleaf Soapweed Yucca
Soapweed Yucca: glauca Soft Maple (spp.)
Soft Maple 'Beebe' Soft Maple 'Pyramidale'
Soft Maple 'Silver Queen' Soft Maple 'Skinneri'
Soft Maple 'Wieri' Soft Tip Yucca
Soldierwood Soledad Pine
'Sombrero' Common Zinnia 'Sonata White' Garden Cosmos
Sonoma Manzanita (spp.) Sonoma Manzanita 'Howard McMinn'
'Sonora' Black-eyed Susan Sonoran Desert Ruellia
Sonoran Palmetto Sonoran tree Beargrass