Green Roof Plant Blog

By Kat Harrold

Photo by Jorg Breuning

Delosperma nubigenum

By Kat Harrold

Photo by ~ Sedumphoto.net

Sedum lydium is an unique globular shaped sedum perfect as a dense ground cover in full sun rock gardens and extensive green roofs spreading to 8-12 inches in diameter and 2-4 inches high.  White flowers attracting butterflies and other pollinators emerge in early summer.  Hardy in USDA zones 5-8, this sedum also offers seasonal interest during the cooler months, taking on a bronze to ruby glow around the edges. 

By Kat Harrold

Photo- Kat Harrold

Sedum hybridum 'Czar's Gold' is a hardy evergreen sedum with striking red stems and year round interest.  Gold flowers pop forth in the spring providing food for pollinators.  This sedum does very well on full sun extensive green roofs and has managed to thrive on our full shade test green roof.  Sedum hybridum 'Czar's Gold' is a great ground cover reaching only 6 inches in height and spreading out in masses of up to 8 inches.  Ideal climate for Sedum hybridum 'Czar's Gold' is between USDA zones of 4 to 7. 

By Kat Harrold

Photo~ Kat Harrold

Crocus are a wonderful green roof plant for extensive to intensive green roofs.  Bright flowers pop forth in late winter to early spring providing the first signs of the warmer seasons to come.  The general rule of thumb when planting crocus bulbs is to cover the top of the bulb with at least three times as much growing media as the bulb is high.  This said the smaller the bulb the greater you success on a shallow roof.  Crocus are wonderfully low maintenance and love the well drained media of the green roof and will do well in full sun to shade.  For the foodie at heart consider planting the saffron fall blooming crocus.  

By Kat Harrold

Photo by ~ Jorg Breuning

Dianthus carthusianorum is a sun loving drought tolerant plant is sure brighten any green roof from extensive to intensive.  Bright magenta flowers pop forth mimicking small fireworks from July to September.  Slender grass like leaves and wiry stems make this a wonderfully drought tolerant selection.  Dianthus carthusianorum prefers well drained soils and grows in small clumps about 10 inches in diameter in 2 inches high with flower stalks reaching about 10 inches in height.

By Kat Harrold

Photo by ~ Jorg Breuning

Sedum kamtschaticum is a hardy evergreen sedum great for extensive to semi-intensive green roofs and will reach up to 6 inches in height.  Star like yellow flowers accent its foliage in the spring and summer providing nourishment for pollinating insects.  This sedum does well in both full sun and is holding as strong as any sedum on our shaded green roof.  Like most green roof plants Sedum kamtschaticum prefers well drained soil with a lite amount of fertilizer during the first few years of establishment.  This sedum is drought tolerant and can be grown from seeds, cuttings, or plugs.    

Photo by ~ Kat Harrold

Sedum spurium 'Fuldaglut' is a very hardy extensive green roof plant that does well in full sun and part shade.  This ornate spreading ground cover has pink flowers in the mid-to late summer and bright red foliage in the cooler months.  From observing our mostly shade green roof this plant is much happier with more sun and does best in the drier areas of the roof.

By Kat Harrold GRP

Sedum album ~ Kat Harrold GRP

Sedum album is a hardy little sedum that creates a very low growing blanket of little green gems tightly clustered together on an extensive green roof. This is one of your staple sedums for extensive full sun green roofs. This is definitely a less is more kind of plant when it comes to water. Looking out our window at our sample green roof that is in mostly shade, it is not terribly happy in that location but is doing its best at the highest and driest points on the roof.

Common Toad Flax, Butter and Eggs

By Jorg Breuning

Linaria vulgaris ~ Photo by Jorg Breuning

Linaria vulgaris is listed by the USDA as noxious weed for several western states.  I believe that this plant can be tolerated on un-irrigated green roofs in states where it is not considered noxious.  This plant helps to prevent wind and water erosion on extensive green roofs.  In a green roof environment it’s height is stunted to 1/4 normally sees on ground dwelling plants.  Linaria vulgaris is also a great food source for honey bees and is not considered a noxious weed in states east of the Mississippi River.  

Tell us what your thoughts are on the use of introduced or non-native plants on green roofs.