Many people's most important lawn care question is: Who should they hire to take care of it? Unfortunately, the lawn industry has been slow to respond to public unease about the overuse of toxic lawn chemicals.

Though more lawn care companies are paying lip service to such concerns, it can be difficult to find ones that really invest the time and skill required to be environmentally friendly.

If you can pay someone to mow, fine. My advice is to do the rest of the lawn care yourself. No one cares about your lawn more than you. Why pay to keep lawn technicians working March to December when your family and the environment are not exactly benefit

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ng from the unnecessary chemicals your land must absorb to keep them so busy?

Surprisingly little needs to be done if you can tolerate a lawn that is less than putting-green perfect. The only two things on the "must do" list are raking leaves and mowing. The other operations are apt to create more problems than they solve.

So here's a brief primer on common sense, low-chemical lawn care:

Fertilizer: Lawn grass is perennial, while most lawn weeds are annuals. Lawn companies like to apply fertilizer in the spring because it helps the lawn to green up more quickly, but this means you're also feeding the weeds. That's why I recommend fertilizing only in September or October, when most weeds are dying off and the grass roots will get all those nutrients. As with most gardening, your goal should be to encourage root rather than top growth.

When you do fertilize, use a slow-acting natural-based fertilizer that improves the soil over time. Organic fertilizers also have more trace elements and won't burn your lawn. Gardener's Supply sells a good Organic Lawn Care Kit that treats 3,000 square feet for $54.95.

Avoid quick-acting chemical fertilizers, which tend to acidify the soil. This hurts earthworms and soil micro-organisms that aerate your lawn and prevent thatch buildup. If you kill them off with too many chemicals, you'll just have to pay someone else to do their job.

Too much fertilizer, especially liquid nitrogen, also makes grass more vulnerable to drought, pests, and disease by making it grow faster than it wants to naturally. Also, when lawns get more nitrogen than they can use, the extra gets washed into local waterways, where it stimulates runaway algae growth that suffocates fish. A green lawn may be beautiful, but a scummy pond isn't.

If your lawn is already dependent on chemical fertilizers, wean it off gradually by using a small amount of low-nitrogen fertilizer during your transitional year.

(Speaking of fertilizer, let's not forget dog urine, which, in small amounts, is good fertilizer. Usually, however, it is delivered in one concentrated spot and kills the grass. If you see a dog peeing on your lawn, water that spot immediately. Dilution is the solution. This works even several hours after the dastardly event, so if you have a particular area that is favored by neighborhood canines (or your own), try to water it daily. Dog damage is sometimes called "green ring disease." The center grass may be dead, but the grass around it has just gotten a nice shot of nitrogen and greens up in a ring around ground zero. So when dogs deliver, reach for the hose and spread the wealth.)

Soil amendments: Your lawn is more apt to need an application of lime than fertilizer. Grass cannot make full use of nutrients unless the soil has a pH between 6.5 and 6.7. Calcium also is one of the secrets of a low-maintenance lawn, so try to find calcitic lime rather than the more common dolomitic lime. Applying a thin layer of horticultural gypsum also will raise your soil's calcium level. Use a cyclone spreader for separate applications of pelletized lime and gypsum if a standard spreader leaves you with "lawn stripes." Don't buy topsoil unless you have an excellent source, because it's usually full of weed seeds.

Soil testing: To find out how much lime to apply and what, if any, fertilizer is needed, buy a kit to test your soil. Some garden centers will do this for you.

Weed control: Herbicides that kill weed seeds before they sprout are much less toxic than poisons applied after weeds have sprouted. Apply a pre-emergent crabgrass control when the yellow forsythia is in bloom. If you want to use an organic one, buy corn gluten, an excellent new product carried by garden centers. Gardens Alive sells a good version called WOW Plus. Don't use a pre-emergent herbicide or corn gluten if you are planting grass seed, though, or that will be killed, too.

Set your mower high and you will have fewer weeds. The fashion for close-cropped lawns weakens the grass and gives weeds the edge. Letting your grass stay at 2½ to 3 inches allows it to out-compete weeds, and the lawn still will be springy under foot.

Seeding: If your lawn is patchy, don't replace it. Thicken it. Rent a seed slicer (about $80 per day), which will plant your grass seed at the appropriate depth. Fill the hopper with seed and run it over your lawn a couple of times, approaching from different angles. Alternatively, use a spreader and rake it in. If you're patching a bare spot, cover the seeded area with a ¼-inch of compost.

Choose a grass seed mix that suits your needs. For instance, consider a "sports turf" mix for areas with heavy foot traffic.

Look for new cultivars of perennial ryegrass and fescues that contain endophytes to increase their tolerance of drought and surface-feeding insects such as chinch bugs. One such mix is Turf Alive III, sold by Gardens Alive. The best all-purpose, cool-season grasses for New England are the fine fescues, according to organic lawn expert Michael Talbot of Mashpee. "The best seed mixes for either shade or sun are the good shade mixes," he says. "I use Ecoblend, which is endophytically enhanced."

Most new grasses are so vigorous that they will crowd out your old lawn, so don't worry about matching the new seed to the existing grass if you over-seed.

Once planted, grass seeds must be kept constantly moist until each has sprouted a couple of leaves, or they will die. This takes about a month. Spring rains help, but when they are absent you will need to water daily. After the first couple of weeks, you can apply a starter fertilizer formulated for lawn seedlings. Don't mow until the new grass reaches 3 inches.

Mowing: This is the most important thing you do for your lawn. Do it high and often, once a week until July, when growth rates slow. If you trim less than an inch off the top, leave the fresh clippings on the lawn, where they quickly disappear and serve as organic fertilizer.

Because they don't have catalytic converters, gas-powered mowers produce as much air pollution in an hour as a car driven 350 miles. If you're concerned about the environment, you like exercise, and your lawn isn't too large, consider one of the old-fashioned reel mowers that have come back into fashion. If you're not up to all that pushing, there are new electric mowers, which are almost equally quiet and non-polluting.