Noell's Grevillea
Norfolk Island Pine, Star Pine
Norway Maple
Oakleaf Hydrangea
October Daphne
Octopus or Midas Agave
Old Man Cactus
Oldham Bamboo, Giant Timber Bamboo
Oleander
Olive, European Olive
Opal Alum Root Hybrid
Orange Clock Vine
Orange Ice Plant
Orange Sedge
Orchid or Purple Rockrose
Oregon Ash
Oregon Grape
Oriental Arborvitae
Oriental Fountain Grass
Otto Quast Spanish Lavender