Florida Green Roofs, Green Roof Plants and Freezing Temperatures

Just got back from Tampa again. I came across some native grasses along the way at a small nursery - and brought them back to Jacksonville. They are low profile grasses - nice green color and light, flowing texture - especially for Winter!

I have already placed them up on the roof.

The weather forecast is calling for temperatures to hit the teens to mid-twenties across North Florida - and into the twenties all the way down into south-central portions of the state.

Record temperatures are expected (record lows that is).

Of course, Judy and I covered our citrus and some of our tender landscape plants.

But the exciting part of the cold is to see just how 'hardy' plants are on the roof. Some of my green roofing plants took a hard hit two weeks ago. They didn't die, but sustained some scarring. Others made it through the cold just fine.

One of the more interesting observations I've seen this cold season is that you can have two identical plants on the roof but one plant has been installed earlier in the year and has had a chance to 'harden' off to the harsh reality of the garden roof, while the other freshly installed plant has not. Not surprisingly - the non-hardened off plant suffered much more damage than the plant installed in the late spring.

This tells me that there are ideal months to install green roofing plants. I'd suggest it is best to install cold-hardy plants during the cooler months and cold-affected plants during the pre-summer season (allow the roots to develop and grow into the engineered medium before the stressful weather hits.

I'll update the condition of the native grasses after tonight's hard freeze.

Happy Green Roofing!