Green roof accent plants

Talinum calycinum. Photo courtesy of Barry Parker

Ed Snodgrass, founder of Emory Knoll Farms and Green Roof Plants in Street, Md., offers some of his favorite accent plants that will add some drama and color to a green roof.

Phemeranthus calycinus (syn. Talinum calycinum)
Known as talinum in the trade, this species is a great plant supplying pollen and nectar for pollinators and blooming every afternoon all summer. Pink to purple five-petaled flowers stand atop long wiry stems. This allows them to be seen by folk not on the green roof.

Campanula rotundifolia 
C. rotundifolia is a widespread American wildflower that ranges from Canada to the Gulf of Mexico. It has an early summer bloom of a pale blue bell shaped flower. It may perish in periods of drought but it is worth replanting.

Aster alpinus 
This is a stunning flower in spring with purple petals and a yellow center with dark green foliage. It is a mountain wildflower and very hardy. There is a darker petal form called A. alpinus Dunkle Schone and also a white flowering variety ‘Alba.’

Delosperma ‘Lavender Ice’
Delospermas are drought tolerant groundcovers with few exceptions. They tend to be floriferous and have long bloom cycles. Delosperma cooperi and D. nubigenum have been the most reliable performers on green roofs ‘Lavender Ice’ is worth a look.

Phacelia campanularia
A desert species from the southwestern U.S. also called California bluebells, this plant works well on green roofs as a food source for bees and other pollinators. It will recede as the green roof fills in, as it needs open soil to germinate.

Sedum pulchellum 
S. pulchellum is a southeastern native that is a biennial but will act like an annual on a green roof. It has showy pink arching flowers in spring. Unlike most eastern native sedums, it is fairly well suited to the conditions on a green roof.

Opuntia aurea
This prickly pear is a pink flowering species with great red winter color. It is slower growing and doesn’t lay flat like O. humifusa, but worth the effort. You may want to invest in a pair of long needle nose pliers for weeding.

For more: Emory Knoll Farms, www.greenroofplants.com.

See more green roof facts from Snodgrass and other experts at www.greenroofs.com.