If you're a city-dweller with no patch of green to call your own, here's a way to bring the outdoors just a little closer. Plant little trees in planters and place them on your balcony.
No balcony? Apply the same idea (on a smaller scale) to some windowboxes. It's amazing what a difference it makes to your frame of mind when you have an up-close view of even just a little bit of nature.
Our kitchen lightwell overlooks the neighbor's roof. So (with permission from the neighbor) we've started a small rooftop garden... just enough to soften the view of tar and gravel.
http://photos.imageevent.com/bats/misc2/rain2.jpg
http://photos.imageevent.com/bats/misc2/Side%20Deck%204.jpg
http://photos.imageevent.com/bats/misc2/side%20deck%20Sunrise.jpg
It was hard to find things that would grow in small, light containers and thrive in the extremes of wind, fog, and sun. Succulents do the best. Annuals, not so well.
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The other, smaller lightwell is surrounded on all 4 sides by tall walls. We've filled it with shade-loving plants... plus one very fake ficus in the back, inaccessable corner.
http://photos.imageevent.com/bats/valleystreet/lightwell%20005.jpg
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