Wow. I drove to Tampa from Jacksonville this week and witnessed first hand the damage last week's twenty degree F temperatures did to horticulture across the state. We must all remember that even south central Florida may be subject to hard periods of cold, freezes and frosts.
Balance. The word that kept popping up in my mind was 'BALANCE'. In designing a green roof for Florida we must keep in mind the 5 H's (they have grown to five from my initial three) - Hurricanes, Heat, Humidity, Heavy Winds and Hard Frosts.
Choose your planting scheme to include three components!
Number One - use the standard green roof plants that survive no matter what. These include plants that come through hard freezes and boiler-type humidity periods. There aren't many of these but there are a few...
Number Two - Select some of the Sedums that will thrive in the winter. They will limp through the summer though. Their poor summer performance can be offset by Number 3.
Number Three - Select those plants that thrive in the summer monsoons but limp through the winter.
A good green roof plant designer will be able to deliver year-round color and interest.
Remember - we focus on non-irrigated Extensive Green Roofs. Roofs that are light weight - no more than a couple two or three inches think.
Florida is tough on Green Roof plants.
Hands on experience through many years or trials is what will produce the best design for each Florida location.
Happy Green Roofing!