How Does Your Garden Grow?
The benefits of a garden roof – reduced stormwater runoff, improved energy performance, and reduced urban heat island effect – are fairly well established. But what you don’t often hear is how beautiful a garden roof can be. In fact, if you’ve ever had the chance to tour one, you know it’s quite an experience. It’s a little bit like being on a mountaintop, and with birds chirping and greenery all around you, it can be very beautiful.
When I became a part of the roofing industry and began working with our GAF Gardenscapes line, of course the first thing I asked – as many do – was “What grows on a garden roof?”. (The other most frequently asked question is “Will it leak?” which I cover in this blog ). The plants that are selected for a garden roof vary by region, but they generally consist of plants that are well suited to extremes of temperature and exposure, and are often low growing. Broadly speaking: things that grow on cliffs are good for roofs.
With my fairly steeply pitched residential roof with conventional asphalt shingle construction (and the fact that my wife doesn’t always share my passion for using the house to test everything), I don’t have the right structure to convert to a garden roof. However, I wanted to try growing some of the plants. Where I live in Maine, I do have some fairly rooflike areas to plant, with extremes of temperature and sun exposure. So I am creating a small plot in my yard, as a kind of a test.
To get started, I built a small platform in my yard, then I called David Gilmore of Etera, a specialist in vegetative roofing horticulture, to ask for tips on selecting the species that would be most suited for my area. Here is what David suggested (the common name is followed by the Latin name):
Kinnikinnick or Bear Berry: Arctostaphylos uva –ursi
Blue Fescue: Festuca ovina glauca
Sea Thrift: Armeria maritime
and an assortment of low growing sedums, the real workhorse of garden roofing: Sedum spurium, John Creech, Red Carpet, Fudliglut, Dragons Blood, Sedum album, Sedum sexangulare, Sedum acre
As I prepare the plot, complete with drainage mat and a simulated roof assembly, I’ll post pictures and update my progress!