No this isn’t a typo, I’m writing about a green roof that has gone brown. The Roy-Fisher Team visited this roof at the Nancy Foster Florida Keys Environmental Center in early June. The Center is currently completing paperwork for a Silver LEED certification and the green roof is included in their LEED point calculations. The building is surrounded on ground level by a thriving native landscape on a drip irrigation system that educates the public on native plants for a LEED innovation point. Although the roof is currently brown, we take our hats off to this pioneering group that built the first green roof in south Florida for a LEED building under the harshest conditions that South Florida can dish out. The roof did survive harsh salt winds, extreme heat and a hurricane until it fell prey to severe drought conditions, staff reductions and other priorities.
Leigh Epsy, the Chief of Staff during construction gave us a very thorough tour. We hammered Leigh with questions: What benefits did she realize from the green roof? Were they seeing a reduction in energy costs? Was their roof irrigated? What was the planting media? How deep was their planting media? What kind of plants did they use? Who designed the green roof? Why did she think it was brown? Did they plan to replant it?
The Center does not have a means to monitor the energy savings realized because of the green roof. Since this is the first LEED registered building in the Keys, it would be difficult to pinpoint which energy savings came from some of the other building features separate from the green roof.
Leigh felt that the biggest benefit of the green roof was stormwater retention. She based the benefit from a visual, not quantifiable assessment. She also felt that the green roof was a great marketing tool for LEED; people notice it. Questions about the green roof become a segue into explaining the concept for the whole building and site.
The original design was done by Charles Beazley from Lafayette, Louisiana. We couldn’t get information on the planting media specification but a Center employee recalls that it was black lava rock. A section we found indicated a 4” planting media depth.
The originally specified plantings were not planted but were replaced with a non-native African marsh grass recommended by a local nursery and it thrived. Once it was discovered that the grass was not native, it was removed and replaced with Spartina Bakerrii and Sea oxeye daisy. A conscious decision was made NOT to irrigate the green roof.
This is what happened:
The green roof was installed with less planting media. The black lava rock got very hot.
Despite the harsh conditions, the green roof thrived at first and actually survived Hurricane Wilma. Leigh recalls that the spartina did much better than the sea oxeye daisy.
In the spring/winter of 2008, the Keys experienced a prolonged drought. At that time, the Center was understaffed due to government budget cuts and, sadly, an employee passed away. The green roof was not a priority; the plants died from lack of water.
There is a happy ending however. The local Master Gardeners have adopted the project and are testing different plant species on the roof including sea purslane and beach elder, two tough native plants that can take salt and heat. The plants are being watered through establishment. We hope that eventually a drip system for emergency situations will be considered. The RFA team plans to get updates from the Center and visit in 6 months to see if the roof is green again.
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