Monday, December 6, 2010

Rooftop Permaculture - Bulbine - Medicinal Plant Also!

Green roof plants can provide many benefits.

Earlier today we posted a photo of a group of Bulbines making up a small green roof.

The green roof was constructed as an erosion control feature.  Prior to the green roof installation, roof stormwater runoff would collect on higher adjacent roofs and then flow down the shingles at high speeds and hit a section of the front porch roof.

The cumulative effect of stormwater hitting the porch roof resulted in chronic erosion of the asphalt shingles and roofing - allowing for eventual leaks.

Once the 1 meter by 1 meter vegetated roofing mat, comprised of a woven synthetic mat, a low VOC adhesive, a waterproofing membrane, engineered soils and the plants, was installed, the Bulbines grew quickly to form an extensive root mat.

The engineered soil layer was less than 1" average depth.

Amazingly, all of the Bulbine root system have interwoven radially into other Bulbines, forming a thick, almost impervious root mat.

The stormwater flows into the Bulbine planting where the water speed and velocity is reduced and calmed.

Finally, in addition to the erosion control benfits of the Bulbine-based green roof - there are many ethnobotanical and medicinal traditions related to bulbines.  Click here for an amazing website detailing Bulbines many medicinal uses.

Happy Green Roofing!


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