By ERIN KENNY

I am proud of the fact that my 4-year-old can identify a whole host of edible plants and tell you which ones are poisonous and which ones we make into medicine.

We spend a lot of time outdoors, not only because I love it but also because I have always intuitively believed kids need to spend a significant amount of time outside every day to stay balanced. Lucky for me, my mother was fond of saying, “It’s too nice to be inside; you kids need to play outside.” We would all then end up spending hours in nature — exploring, building, examining, climbing and creating elaborate games without structure or adult supervision. Our feet on the earth, breathing fresh air, surrounded by trees and plants, we felt at home in the great outdoors.

Today, kids are spending significantly less time outside than in any previous generation. The statistics are shocking. According to the organization “Playing for Keeps,” more than 80 percent of children under age 2 and more than 60 percent between the ages of 2 and 5 do not have access to daily outdoor play.

And just what is replacing outdoor time? According to a Kaiser Family Foundation study, the average American child spends 44 hours per week (more than six hours a day) staring at some kind of electronic screen, with the average 2-year-old spending more than four hours a day in front of a TV or computer screen.

I first heard the term “nature deficit disorder” when I read Richard Louv’s seminal book “Last Child in the Woods.” One of the primary symptoms of the disorder is the replacement of the green space by the screen space as the occupier of children’s free time.

In his book, Louv makes the rather convincing argument that most children today do not have the kind of exposure to nature that leads to empathy for the natural world, and studies have found that leading environmentalists all had a conspicuous background of direct experience with nature as children. Louv is careful to distinguish between structured and unstructured outdoor time, and he is specifically decrying the lack of unstructured time that kids today have compared to their parents’ generation.

According to the National Wildlife Federation (NWF), children who regularly spend unstructured time outside play more creatively; have lower stress levels and more active imaginations; become fitter and leaner; develop stronger immune systems; experience fewer symptoms of attention deficit disorder (ADD) or attention deficit hyperactive disorder (ADHD); and have greater respect for themselves, for others and for the environment. Consequently, the NWF has started promoting the concept of the “green hour” — the idea that children need a casual hour outdoors each day in the same way they need a good night’s sleep or a vitamin.

In its March/April 2004 issue, Psychology Today published the results of a study which found that spending time in ordinary “green” settings — such as parks, farms or grassy backyards — reduces symptoms of ADHD when compared to time spent at indoor playgrounds and man-made recreation areas of concrete and asphalt. The researchers recommended that children with ADHD spend some quality after-school hours and weekend time outdoors enjoying nature.

Lawmakers are beginning to understand the importance of outdoor time and are attempting to institutionalize the concept. Legislation was recently introduced in both the U.S. House and Senate that strengthens and expands environmental education in America’s classrooms and reconnects children with nature. These two bills, both titled the No Child Left Inside Act of 2007 (H.R. 3036 / S. 1981), provide federal funding to states to train teachers in environmental education and operate model environmental education programs, which include outdoor learning.

For myself, I often forget that there are people who regularly do not spend time outdoors, just doing nothing. It has always been so much a part of my daily routine, and I know it nourishes me. Recent research has supported what I have suspected all along: It is vitally important to your children’s physical and mental health to spend quality time outdoors every day.

— Erin Kenny can be reached by way of her Web site at www.cedarsongnatureschool.org.