o'er the lovely midtown prairie on the 8th floor

Last summer our office, which is on the penthouse floor of an 8-story building in Chelsea, installed a planted garden over the roof terrace outside our windows. This is actually the roof to the floor below our office--there is a large setback between the 7th and 8th floor. Before, it basically provided an expansive and not so pleasant view of black asphaltic roofing from the window wall of our office. The garden was meant to create a more bio-philic (office buzzword of the year) vista, and function as a testing ground for implementation of similar systems in our projects. There are potentially great benefits from using planted roofs to helps cities deal with the urban heat island effect, excess storm water runoff, and carbon emissions.



Because we wanted to avoid having to reinforce the existing roof to support the weight of the garden, or spending many many dollars, we used a system of burlap bags filled with lightweight rocks, styrofoam bits, and a very little bit of soil, which we laid over a root barrier and drainage mat onto the roof. We then cut holes in the sacks and planted 8 varieties of sedum plants, specially selected for their hardiness in very windy conditions (8th floor rooftop) and because after the first month, they require no irrigation.



A year later, the roof is beautiful! It had a wonderful and unanticipated flowering season in April and May but now it's settled into a palette of greens, browns, and yellows. Last weekend we augmented the original plantings with a border of pavers and a few more rows of slightly taller-growing plants around the perimeter.