Green Roof Plant Blog

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.

Circle Onion

By Kat Harrold

Allium sensescens ~ Photo by Kat Harrold

Allium sensescens is a showy end of summer to early autumn bloomer that does well in both full sun and full shade.  Its light pink pompom is about an inch in diameter and somewhat resembles a beach ball floating across a sea of gray green wavy leaves.  A fragrant member of the Alliaceae family, it can contribute to a bouquet of scents in a floral herb garden.  This plant is most suited for extensive to semi-intensive green roofs and requires little maintenance.

Hieracium maculatum  - Kat Harrold

Hieracium maculatum is a great green roof plant for full to part shade green roofs.  Soft hairs on the leaves help it adapt to dry sunny locations as well.  Plants less than a year old may require extra attention in areas of full sun during extreme heat and drought conditions.  Given proper nutrients and water this herbaceous plant is repeat bloomer and can provide a spray of bright yellow flowers from early to late summer.

Hieracium maculatum may be grown on a green roof either from plugs or seeds.  It is best suited for extensive to semi-intensive green roofs.