Spring is here -- a time of renewal not only for plants but for long-dormant lawn-care tools. The buzz of mowers and swish of sprinklers once again fill the air.
Despite their soothing appearance, lawns inspire a fair amount of concern. Homeowners want good-looking turf, but aren't always sure how to achieve it. And then there are environmental consideration about pesticide use, water, and pollution from mowers.
In the last two years, books have come out with provocative titles, ''The Lawn: A History of an American Obsession,'' (Virginia Scott Jenkins, Smithsonian Press) and ''Redesigning the American Lawn: A Search for Environmental Harmony'' (F. Herbert Bormann et al., Yale University Press).
One emerging trend is the rise of ''eco-lawns'' that include flowering, broad-leafed plants as well as a base of roughly 80 percent grass. The added plants provide natural fertilization and reduce the need for water, mowing, and pesticides.
For many homeowners who have an existing all-grass lawn and are not sure what to do, the answer lies in a lawn-care service.
''I try to mow it and let the experts do the rest,'' says Michael Mogan, a Seattle resident with an enviable blanket of sod leading up to his door. Still, he recently switched lawn services ''because of nagging concern'' about one company's use of chemicals. The sprays may have been drifting onto neighbors' lawns, he worried.
But most people -- some 54 million United States households -- look after their own lawns, according to the National Gardening Association in Burlington, Vt. These weekend warriors spent an average of $166 each on various lawn products last year, from fertilizers to sod and mowers.
''Based on our work, we are confident that a lot of people don't know what they're doing,'' says researcher Terry Cooper at the University of Minnesota.
Among the common problems he found in the upper Midwest: using fertilizer with too little nitrogen and potassium, and too much phosphorus. None of 21 homeowners he tracked had their soil tested, and only nine applied fertilizer in the fall, a critical time since photosynthesis is at a peak. (One place to get soil tested is at the County Cooperative Extension Office your state maintains.)
Tom Cook, an Oregon State University turf expert, says many people also misuse herbicides.
''Most people say, `it's spring -- time to use the weed-and-feed,' ... whether they need it or not,'' Mr. Cook says. ''If the lawn is healthy, then the lawn itself can keep out the weeds.''
But if weeds do become a problem, people often fail to do a second application of herbicide two weeks after the first. ''The key to killing them is that second treatment,'' after which lawns may go for years without developing a weed problem, he says.
Cook has become a pioneer in developing the so-called eco-lawn from his base in Corvallis, Ore.
''We basically have never fertilized these mixtures, and never had to spray with herbicides,'' he says. The mixture he has found to be optimal in the Northwest is a rye-grass base with white yarrow, strawberry clover, and English daisy. Commercial eco-lawn mixes often also add chamomile for its sweet fragrance.
A handful of companies have come out with versions of the eco-lawn, some just in the past year. These include Smith & Hawken in Mill Valley, Calif., and Hobbs & Hopkins (a product called Fleur de Lawn) in Portland, Ore.
Bill Marks, co-owner of D. & F. Marks in Woodinville, Wash., views his new Ecoturf as a niche product for people who want drought-tolerant landscaping, but with something they can call a lawn.
''Water is a precious commodity,'' he says, calling eco-lawns ''a sign of things to come.''
Cook says that eco-lawn's water-saving capacity could be a boon in areas with water shortages. In the hot, dry Corvallis summer, Cook says his eco-lawn needs only four waterings a year, yet still looks green. It needs mowing just once every three weeks, versus once a week for all-grass lawns during the growing season.
As for prices, Ecoturf sells for about $17 a pound, and Smith & Hawken's flowering lawn mix goes for $49 a pound. While plain grass seed generally costs less, Mr. Marks says, more of it is needed. Ecoturf needs about 2 pounds per 1,000 square feet.
To create an eco-lawn, you need to start from scratch, Cook says, rather than trying to add flowering plants into an existing lawn.
Debra Byrne, owner of the Garden Shed retail store in Seattle, says that some people mix their own seed, rather than buying premixed lawn seed.
Despite his work to develop eco-lawns, Cook won't criticize traditional all-grass lawns, saying they are unjustly attacked. Fertilizer nutrients have been blamed by environmentalists for running off into lakes and causing algae and millfoil growth. Cook says research at Pennsylvania State University suggests this doesn't happen, even with sloping lawns severely overwatered after fertilizing.