Simon Bamboo Variegated Simpleleaf Vitex (spp.)
Simpleleaf Vitex Variegated 'Simplicity' Rose
Simpson's Stopper Sinaloan Silk Tree
Singapore Holly 'Singin in the Rain' Rose
'Singing Sixteen' Daylily Single Leaf Pinyon
Single Leaf Pinyon Pine 'Single Red' Hybrid Peony
Singleleaf Pinyon Singleseed Juniper (spp.)
Singleseed Juniper 'Blue Carpet' Singleseed Juniper 'Blue Star'
'Sioux Falls' Coral Bells: sanguinea 'Siouxland' Carolina Poplar
'Sir Charles Lemon' Rhododendron: hybrid 'Sir Joseph Banks' Bigleaf Hydrangea
Siris Tree 'Sirius' Daylily
Sisi 'Siskin Clock' Carnation: Dianthus
'Siskiyou Blue' Idaho Fescue Siskiyou Cypress
'Sissinghurst White' Jerusalem Cowslip 'Sister Agnes' Oleander
'Sister Therese' Bigleaf Hydrangea Sitka Mountain Ash
Sitka Spruce 'Six Hills Giant' Catmint
Six Week Grass 'Sizzler Burgundy' Scarlet Sage: splendens
'Sizzler Lavender' Scarlet Sage: splendens 'Sizzler Lilac Bicolor' Scarlet Sage: splendens
'Sizzler Mix' Scarlet Sage: splendens 'Sizzler Salmon' Scarlet Sage: splendens
'Sizzling Pink' Chinese Fringe Bush: chinense 'Skagit' Oriental Spruce
'Skandia' Savin Juniper 'Skeeter's Broom' Japanese Maple
'Skeleton Key' Foamflower: Tiarella Skimmia 'Kew Green'
Skimmia, Japanese (spp.) Skimmia, Japanese 'Cecelia Brown'
Skimmia, Japanese 'Rubella' Skimmia, Japanese 'Snow Dwarf'
'Skinneri' Silver Maple 'Skippy XL Red-Gold' Horned Violet
'Skogholm' Bearberry Cotoneaster Skullcap
Skullcap, Bushy Blue Skullcap, Pink
Skullcap, Pink Texas Skullcap: suffrutescens
Skunk Cabbage Skunk Cabbage: foetidus
Skunk Tree Skunkbush
Sky Flower 'Golden Edge' Sky Flower 'Sapphire Showers'
Sky Flower Variegated Sky Flower: auriculata (spp.)
Sky Flower: auriculata 'Imperial Blue' Sky Flower: auriculata 'Royal Cape'
Sky Flower: auriculata White Sky Flower: grandiflora
'Sky Magic' Garden Petunia 'Sky Pencil' Japanese Holly
Sky Pilot 'Purple Rain' 'Sky Pointer®' Japanese Holly
Sky Vine 'Skybound' Sugar Maple
'Skylands' Oriental Spruce 'Skylark' Blueblossom
'Skylark' Holly Grape 'Skylark' Oregon Grape
'Skyline Neon Lights' Garden Petunia 'Skyline Purple Haze' Garden Petunia
'Skyline' Thornless Honey Locust 'Skyracer' Tall Moor Grass
'Skyrocket' Alumroot: Heuchera 'Skyrocket' Colorado Red Cedar
'Skyrocket' Rockcress Slash Pine
Slash Pine: elliottii Sleepydick
'Sleigh Bells' American Holly