This a small green roof we did in 2008 at Rob Overly's house in Jacksonville. It is small (4' x 4') but in a very hot, harsh spot with on shade.
Rob, being the sustainable architect with a flair for clean water - being the water guru for Rotary International and traveling the globe on a mission of Sustainability - approached me and asked if we could do a pilot green roof on his front porch. Using TPO over shingles and our mat and soil we planted the green roof using garlic chives, yuccas and bulbines. Much to my surprise - two years later, the bulbines are the survivor champs. Now birds, pollinators, tree frogs and anoles use the green.
I would have thought the winter cold would have killed them. I would have guessed the garlic chives would be the surviving species. However since this was to be a prelude to inexpensive technology in rural mother earth, one of the design criteria was a engineered soil layer of 3/4 inches of less. This is probably why the garlic chives did not survive. The TPO serves as the root barrier, and doing an excellent job at keeping roots out of the shingles.
This is an non-irrigated green roof that has survived temps ranges of 10 degrees F to 150 degrees F (measured on leaf surfaces with ExTech InfraRed). Periods of no rain up 9 weeks and periods of intense inundation.
One of the reasons the section of roof shown was chosen is because it receives runoff from a long valley on the above roof and during a serious rain event there is a flood coming across the vegetation.
Call us with your green roof requirements.