How to plant a green roof?

WGBH is planting roots along with the solar arrays on the rooftop of its new building in Boston's Brighton neighborhood.

Click here to watch a Somerville company take the final steps in making the rooftop garden happen, with special soil and vegetation that can withstand wind gusts and drought.

Here's more from WGBH, and click here for Robert Campbell's review of the building itself.

Green roofs already exist on Boston's World Trade Center, the Four Seasons Hotel and
Massachusetts General Hospital, according to this article. The Apple Store that just opened on Boylston St. in the Back Bay put in a green roof as well (here's a posting on it by the Globe's Hiawatha Bray.)

Proponents say a hot summer day pushes up conventional roof temperatures to 150-plus degrees, but a green roof's summertime temperature (in Boston) tops out around 90, keeping the building below cooler -- and saving energy.

The roofer didn't do it alone. Karen Weber's Earth Our Only Home, Inc., of Roslindale, worked in conjunction with National Grid to provide advice, funds and contract for the installation. National Grid paid for the first phase of the project, and more help came from Apex Green Roofs, a local contractor of Philadelphia-based Roofscapes, Inc.