Lush, green lawns add aesthetics and coolness to any yard, but what happens to the pesticides and fertilizer it takes to grow them?

Lush, green lawns add aesthetics and coolness to any yard, but what happens to the pesticides and fertilizer it takes to grow them?

They get washed into Bear Creek, the Rogue River and eventually the ocean every time you water, harming fish and prompting algae growth that robs streams of oxygen.

But starting today, Earth Day, lawn growers can avoid using harsh chemicals by creating a few new, eco-friendly habits, says Ajit Singh of Phoenix Organics in Phoenix. They include aerating lawns and applying mycorrhizal bacteria, which stimulate growth of natural soil organisms, then sprinkling organic, all-purpose fertilizer, which feeds the soil all it needs.

The idea is that you feed the soil, not the grass. Healthy soil, fed by compost and natural fertilizer, creates thick, weed-resistant grass, has higher resistance to pests and drought, and the runoff doesn't hurt streams and fish, Singh says. Chemicals kill healthful soil bacteria, he adds.

A 50-pound bag of organic fertilizer is $35 and feeds 5,000 square feet. It should be applied at the beginning of spring, two months later and again before winter.

Singh advises getting in the compost habit. Dispose of all plant waste in a compost bin, where it breaks down and recycles into lawn and garden food. Put a half-inch of this on soil at the start of the season.

Healthy grass, composted and unladen by artificial chemicals, resists weeds, so applying herbicides isn't necessary. In transitional lawns that are recovering from a chemical diet, there will be some weeds, notes Singh, and the best way to get rid of them is the old-fashioned way — by pulling them out.

"Lawn converted from chemical use has less of a weed problem as the roots get stronger and you're introducing good bacteria," Singh says. "Once the root system is strong, it can compete successfully with weeds."

If it's a new lawn, mix compost in the top 2 to 4 inches of soil, add the mycorrhizal material, then add 10 pounds of organic fertilizer per 1,000 square feet, spread low-maintenance grass seed and let it germinate, he says.

Another tactic that reduces water waste and runoff is to adjust your mower upward and keep your grass 3 or 4 inches high. With thicker, higher grass, your soil stays more moist, your grass better watered and you won't have patchy die-offs.

Richard Ulrich, who runs an Ayurvedic Center in Phoenix, uses Singh as his "lawn doctor." Ulrich applies bags of Natural Intention NPK-934 (nitrogen-phosphate-potassium) on his half-acre of lawn.

"It's a carpet of grass. Sometimes I can't believe I live here. The seed is from the Grange (Co-op), made of three types of hardy rye, specifically for this valley."

People come to the Ayurvedic Center for health-related needs and the grounds must be as pure as possible, he adds, with none of the "traditional fertilizers that are oil-based, with heavy metals that get in the way of natural enzymes and bacteria in the earth and impede growth. The natural worms and bugs people have problems with, I don't have any problem with."

With healthy soil and lawn, Ulrich says he doesn't have to thatch (rake out dead grass and debris) — and he carts off lawn clippings for compost.

Pam Rouhier of the Grange Co-op in Medford, who teaches lawn care to Master Gardeners, supports the chemical-free lawn habit.

"The only real and absolute way to make sure you're not creating dangerous runoff is not using dangerous chemicals," she says.

The Grange sells both chemical and non-chemical fertilizers but Rouhier notes, "The right amount of chemical fertilizer is fine, but some people put on a lot. If you see water running down the street, it's getting into the (stream) system and that's not good."

Rouhier adds, "Chemical fertilizers can put too much nitrates in water and they end up in the ocean. They encourage algae growth and that takes oxygen out of the water. "¦ In organic fertilizer, nitrogen releases much more slowly, so it's taken up (by grass) more slowly."

The weedkiller 2,4-D zaps everything but grass and "it gets everywhere. It's quite harmful and poisons fish."

There are no organic weed killers that differentiate between grass and weeds, but you can use citrus oil to kill weeds on walkways and on spots in gardens, she adds.

As an organic fungicide, the Grange sells Serenade, a bacillus. It's a concentrate, costing $11 for enough to make 20 gallons. To help fight fungus, you also want to avoid watering late in the day, which leaves water sitting on the grass all night, Rouhier says.

Instead of using a "pre-emergent" to stop weed seeds before they start (it's dangerous to fish), use corn gluten meal, costing $10 for 10 pounds, she says.

Some herbicides and pesticides are "pretty deadly," injuring and killing fish, and are not approved for use near waterways, says Craig Harper, natural resources program manager with the Rogue Valley Council of Governments.

"We can say confidently that in the summer, when streams are low, pesticides and fertilizers can cause die-off because of lack of dilution (of streams) and the fish are already stressed out by low dissolved oxygen, high temperatures and other contaminations," says Harper.

The message, he adds, is use alternatives to pesticides and chemical fertilizers, keep such chemicals out of gutters and storm drains, and if you see your lawn water in the street, know that it's going to end up in streams. Storm drains along streets don't go to wastewater treatment plants, but straight into the creek.

John Darling is a freelance writer living in Ashland. E-mail him at jdarling@jeffnet.org.