There are green roofs and "living walls" like this one. Both provide insulation to a building and, in the case of walls, another aesthetic option for building designers.
They can also help manage water, either by cutting down on run-off or recycling gray water, the water from sinks and baths.
This green wall system from G-Sky is mounted on a frame with a drip-feed water system that can be remotely controlled. A moisture sensor is there to prevent overwatering.
Representatives from G-Sky said they normally grow plants for six months before installing them in restaurants or commercial buildings. These poor plants don't look so happy because they were stuck in there a day before for the trade show.
Photo by Martin LaMonica/CNET News.com
Caption by Martin LaMonica