Tips to help you grow grass that's as pretty as a pedicure.

Caring for your lawn is a balancing act. There are four things you need to do-mow, feed, water, and weed. One influences the other. For example, water and fertilizer make your lawn grow faster so you mow more often. The key is striking just the right balance to minimize input while keeping the lawn healthy.

MOWING

Frequent mowing at the proper height keeps your lawn thick. A dense carpet of turf competes with invading weeds and withstands foot traffic. Meanwhile, a lawn that is allowed to grow tall during a two week vacation and then is cut back to its original height will be left thin and weakened. Weed seeds find their way to the surface of the soil and take hold. Thin turf is easily torn or uprooted when a 10-yearold rounds third base, leaving an even larger opening for weeds.

* How often should I mow? When you mow depends upon how fast your lawn is growing. The rule of thumb is never to remove more than one-third of the grass blades. When moisture is plentiful and the lawn is well fed, you may have to mow every four to five days to keep it at the desired height. If the weather has been dry, the lawn's growth will slow down. Delay mowing until after watering or rain. Mowing a parched lawn will open it up to sun and wind, leaving it even drier.

* How tall should my lawn grow? The ideal cutting height can vary with the type of grass. During the hot, dry months of summer, it is a good idea to let it get a little taller. (See the chart on page 106 for recommended heights.) By letting your lawn grow to the taller end of its range, you will have deeper rooted turf that is more resistant to both weeds and drought * Should I bag the clippings? Collecting the clippings gives a neat appearance, but this also removes nutrients from the lawn. If you can mow often and not let the clippings get too long, a mulching mower does a good job of chopping and blowing the clippings into the turf where they break down and release their nutrients back to the soil. Mulching mowers will not increase thatch.

WATERING

Proper watering will ensure a lawn that is deeply rooted and drought tolerant. If you water correctly, you can get by with watering less often.

* How difficult can it be? Watering is not hard, but some understanding helps. If you apply only a little water every few days, you will moisten the soil only 2 to 1 inch deep, and that's where the roots will be. However, if you water deeply and less often, the roots will grow several inches deep, and they'll stay moist there for a longer period of time.

* How do I know when to water? Wait until you see signs of stress in your lawn before you water. If footprints remain in the turf, the blades are too limp to spring back. Also, a grayish cast to the lawn indicates that it is dry and needs water.

FERTILIZING

* How much should I apply? The general rule is 1 pound of nitrogen per 1,000 square feet. If the fertilizer is 16-4-8, it is 16 nitrogen. To calculate how many pounds of this fertilizer you will need to deliver 1 pound of nitrogen, divide 100 by 16. The answer is 6.25.

However, this is just a starting point. If your lawn is growing too vigorously, gradually reduce the amount you apply.

* How often should I fertilize? Because you want to fertilize when the lawn is growing, cool-season lawns, such as fescue, and cool-season blends will need to be fed in early fall (September), late fall (November), and spring (late February/ early March). You may want to use one of the low-nitrogen, high-potassium winterizing formulations such as 8-&25 for your late fall feeding and calculate the rate as 1 pound of potassium (instead of nitrogen) per 1,000 square feet.

Warm-season lawns such as Bermuda, St. Augustine, and Zoysia need to be fed in the spring (two weeks after the grass turns green), summer (late June or early July), and fall (late August or early September). The exception is centipede. It will decline if overfed. Fertilize in spring only and choose a product formulated for centipede. It will contain iron as well. U Which product should I buy? Look for a fertilizer that is at least 30 slow-release nitrogen. That means that the fertilizer granules will dissolve slowly, and the nutrients will not wash into the neighborhood creek with the first hard rain.

WEEDING

The best way to control weeds is to have a healthy lawn that chokes them out before they get started. Don't mow your lawn too short, and be sure to fertilize adequately. Beginning a good maintenance program will bring many weeds under control within a growing season without chemical intervention.

* Which weed killer should I use? Before applying any chemical, know what type of grass you have and the type of weed you want to kill. Always read product labels carefully because some lawns (especially St. Augustine) can be damaged by weed killers.

A pre-emergence weed killer is applied before the seeds germinate in the lawn. You know seeds are there because you had weeds last year. Some of these products are combined with fertilizer; others are sold separately.

A post-emergence weed killer eliminates weeds that you can see. It may be combined with fertilizer in a product called weed-and-feed, or it may be sold separately as granules or as a spray. To be most effective, it should be applied in warm weather when the weeds are growing.