Hey Mr. Green, How can I get a healthy-looking lawn without using environmentally damaging fertilizers and herbicides? --Jeff in McLeansville, North Carolina

You have good reason to be concerned about lawn care. A hefty portion of the 100 million pounds of household pesticides Americans purchase each year is poured on their yards and can end up in streams and groundwater. Meanwhile, we burn about 300 million gallons of gas annually in lawnmowers. Some petrol-powered models can emit as much pollution in an hour as an old car driving for 100 miles. So my first impulse is to tell you to rip out that grass and grow something more interesting, like herbs, native plants, and vegetables. That's what I did. I figure I'll have all the lawn anybody could ever want soon enough in my cemetery plot.

If you can't live without a big green square of homogeneous turf, here's a program to maintain it naturally: (1) Aerate the soil, either by using an aeration tool or a garden fork or by walking around with those weird spiked shoes available from garden suppliers. (2) Apply an organic fertilizer in spring (before growth) and fall. (3) Mow up to three inches high to give the grass the opportunity to shade out weedlings. (Never cut off more than one-third of the lawn's height.) While you're at it, save money on a gym membership and invest in a nonpolluting push mower.

(4) Recycle the clippings as mulch by leaving them on the lawn; if the grass clumps, just rake it around. (5) Instead of spraying poison, remove weeds, roots and all, by hand. Too lazy or decrepit to get down on your knees? Check out gardening catalogs for some nifty weed-extracting devices. (6) Water deeply and early in the day and only when the grass appears to need it. (7) Put up a bird feeder to encourage visits from winged pest-eaters. (8) Use a soil-testing kit or have the soil tested by your local Cooperative Extension Service to make sure it's around 6.5 pH, which most grasses prefer, and amend if needed.

Remember: None of the above will work without enough topsoil and the right species of grass for your region. And eat your dandelions, children: A cup of chopped leaves has almost 40 percent as much calcium as a cup of milk, plus plenty of other nutrients.

Hey Mr. Green, I attend a lot of baseball games, where it seems that most people find it acceptable to drop food and trash on the stadium floor. While most ballparks have cleanup crews, doesn't this mean less recycling and more landfill? Can I still do my part for the earth while rooting for my team? Go Giants! --Mary in Larkspur, California

Given the advanced age of the Giants' players, recycling and disposal are understandably on your mind. Seriously, though, you'll be happy to learn that the Giants seem to be doing a pretty decent job. They recycle more than 1,760 tons of food scraps, cardboard, paper, and bottles annually--well over half the waste generated in the ballpark. This saves the team about $100,000 a year in disposal costs, almost enough to pick up an ancient knuckleballer. The Giants' rivals across the bay, the Oakland Athletics, are doing them one better: They're introducing compostable cups, utensils, and food containers at their ballpark.

To find out what other teams' stadiums are doing--and get ideas to prod your local club--visit epa.gov/region9/waste/features/stadiumrecycling or contact EPA staff involved with stadium programs at (415) 972-3324.

Read more advice from Mr. Green, including his Web-only mailbag, and submit your own environmental questions at sierraclub.org/mrgreen.

Mr. Green illustration by Melinda Beck; used with permission.