The Toughest of the Tough: Plants for Greenroofs
For 20 years, Cynthia Tanyan has designed over 500 varied residential gardens throughout the SF Bay Area and beyond, including a master plan for a Stanford Lands horsepark, a rural cemetery in Massachusetts, a Native American sculpture garden, and an extensive modern greenroof.
Cynthia's designs have been featured in Sunset (she is a recipient of Sunset's "Best in the West" and "Dream Gardens" Award) and People magazine. Her designs can be seen in The American Meadow Garden, by J. Greenlee (c.2009), and Reimagining the California Lawn, by C. Bornstein.
Greenroofs are tough environments for plants as they are usually exposed to all-day sun, wind, drought conditions and have only a shallow root zone. This is similar to native conditions for many rock garden and succulent plants. Sedums of all kinds are the mainstay for greenroofs. Choose plants that are tough, stay fairly low to the ground, and don’t require much deadheading or other maintenance.
Perennials/Shrubs/Ground covers:
Achillea millefolium, COMMON YARROW
Dymondia margaretae, SILVER CARPET
Juniperus (low growing varieties) time for a comeback?
Nepeta ssp., CATMINTS
Phacelia grandiflora, LARGE-FLOWERED PHACELIA
Rosmarinus officinalis cvs., GROUNDCOVER ROSEMARY
Thymus serphyllum cvs., CREEPING THYME
Grasses:
Bouteloua gracilis, BLUE GRAMA GRASS
Calamagrostis foliosa, MENDOCINO REED GRASS
Carex pansa, DUNE SEDGE
Festuca amethystina, TUFTED FESCUE
Succulents:
Agave pumila, MINIATURE AGAVE
Agave victoriae-reginae, QUEEN VICTORIA AGAVE
Aloe aristata, LACE ALOE
Crassula capitella, ‘Campfire’, CAMPFIRE CRASSULA
Dudleya pulverulenta, CHALK DUDLEYA
Euphorbia tirucalli ’Sticks on Fire’, RED PENCIL TREE
Mangave, ‘Bloodspot’, BLOODSPOT MANGAVE
“Sedum carpet” (available at Succulent Gardens)
Sedum album, STONECROP
Sedum reflexum, ‘Blue Spruce’, BLUE SPRUCE STONECROP
Sedum rupestre ,‘Angelina’, GOLDEN SEDUM
Sedum spurium cvs., DRAGON'S BLOOD
Sempervivum spp., HENS AND CHICKS
Senecio serpens, BLUE CHALKSTICKS