LAST CHILD IN THE WOODS: Saving Our Children from Nature-Deficit Disorder by Richard Louv

For years, James Sallis has been studying why some children and adults are more active then others. He is program director of the Active Living Research Program for the Robert Wood Research Foundation, a multi-year effort to discover how to design recreational facilities and whole communities so they stimulate people of all ages to be more active.

Based on previous studies, we can definitively say that the best predictor of preschool children's activity is simply being outdoors, says Sallis, "and that an indoor sedentary, childhood is linked to mental health problems."

The idea that natural landscapes, or at least gardens, can be therapeutic and restorative is, in fact, an ancient one that has filtered down through the ages. Over two-thousand years ago, Chinese Taoists created gardens and greenhouses they believed to be beneficial for health. By 1699, the book  English Gardener advised the reader to spend "spare time in the garden, either digging, setting out, or weeding; there is no better way to preserve your health.