Q. I would like to know if you have a year-long fertilizing schedule. I would like to fertilize my lawn myself instead of using a service. My yard is St. Augustine grass. Mainly I would like to know when to fertilize, when to treat for brown patch and anything else about lawn maintenance.

- J.S.K., The Woodlands

A. My lawn fertilization schedule is simple: once in the spring when the grass is greening up and beginning to grow, and once in the fall to encourage good root development over the winter months.

I rely on the decomposition of grass clippings during the summer to provide an ongoing supply of nutrients.

Proper culture will encourage a healthy lawn, your best weapon against insects and disease. In addition to proper fertilization, this means proper mowing and watering.

While waiting for grass green-up and active growth, you could mow, removing an inch or so of any brown grass and weed tops, but not so low that the machine damages the St. Augustine stolons and creates bare patches of soil. "Scalping" your lawn will not make the grass green up more quickly.

In years that spring rains are not adequate, it's necessary to water deeply to encourage strong root growth.

Aerate the soil, too. This helps sunlight reach the roots and improves air circulation. Aeration also helps break down any buildup of thatch, or collections of decomposing stolons, roots and other organic material. An excessive amount of this fibrous material blocks the movement of air, water and nutrients to the root system. A thin layer, on the other hand, helps hold moisture in the soil and helps prevent soil compaction.

To aerate the soil, use a pitchfork, poking it in the ground all over the yard. Or rent a plugger, a gas-powered device that makes larger holes. Occasionally, aeration shoes with cleats are available in garden centers. Walk around your lawn in these or another type of cleated shoe.

Soon, you'll notice the lawn is beginning to green up and you'll see active lawn growth. Mow again and fertilize. I suggest a fertilizer that releases nitrogen slowly. Too much nitrogen absorbed too quickly promotes good top growth but not much root and side growth. And those of us with bald spots in the lawn want side growth. Bare spots are an invitation to weeds.

A fertilizer with a 3-1-2 ratio is often recommended for lawns. There are other good ratios available. Ask your nurseryman to help you determine which is best for your needs. The first number of the fertilizer formula represents nitrogen, the second phosphorus and the third potassium, which promotes root growth.

When the lawn is rapidly growing, mow weekly and mow at the proper height. The recommended height for St. Augustine is 2 to 3 inches. A 3-inch height will better shade the soil in summer, which in turn conserves soil moisture.

Remember, the more blade left, the better the grass plant produces food, and as a result, the longer the roots grow. When we mow, we shock the grass. When we constantly cut the blades too short, food production drops, and the roots slow down or even stop growing. Then the grass plants are weakened, becoming more susceptible to disease and the stress of heat and drought.

Leave the grass clippings when you mow. Since clippings are 80 percent to 85 percent water, they decompose rapidly and provide additional nitrogen for your lawn. Studies show that as clippings break down, they return 20 percent or more of their nitrogen content to the soil. A mulching mower will give you a cleaner look, as the machine blades finely chop the grass. Small pieces break down, or decompose, more rapidly, too. Think of all the plastic bags you will save by not bagging clippings, and most important, how you'll avoid contributing to our overflowing landfills.

If you are unable to mow one week and the grass gets too long, either mow it twice to chop the clippings more finely or catch the grass in a bag and use it in your compost pile.

Grass clippings do not contribute to thatch buildup unless you frequently leave long clippings on the lawn. Thatch mostly consists of stolons and other grass parts that are breaking down too slowly. A thick layer of thatch keeps water from reaching roots, and it can harbor pests. If you have a half-inch layer of thatch, rake it up. Aerate the soil and increase soil organic matter.

Grass needs as much as 1 to 2 inches of water a week to grow. We often get more than this. But during the summer, we may need to help out with the garden hose. You'll know water is needed when you walk across the lawn and the blades remain flattened. Their color may be dull. Water the lawn deeply to encourage roots to grow downward. If you sprinkle lightly and frequently, the roots will rise to moisture near the soil's surface where they will dry out more quickly - and sometimes die in summer.

Don't waste water. Don't turn your sprinkler on full blast when it's windy. Avoid watering during the heat of the day. Water slowly so the moisture can soak into the soil without running off. There will be less evaporation with early-morning watering. This also allows the blades to dry during the day, reducing the opportunity for fungal problems.

Correct drainage problems, if possible.

Matters become worse when we put off mowing, then cut off long lengths of grass and allow these to fall on top of the dead roots. This debris compacts into a mat. New grass roots begin to grow in this mat where there are few nutrients and no protection from the hot sun. The lawn starts to die.

Some people fertilize throughout the growing season, but I let clippings boost nutrients. Some studies show, too, that frequent fertilization promotes fungal diseases. I do think it's a good idea to fertilize the lawn in the fall with a formula that will encourage root development over the winter. You don't want a lot of top growth at this time.

Two matters always come up in lawn discussions: weeds and disease.

The healthier your lawn, the less trouble you'll have with weeds. Weeds can be pretty visible in late winter before the lawn begins to grow, but I try to be patient and tolerate those that wander into our turf.

Lawn weeds are broken into two groups: broadleaf weeds and grassy weeds. There are annuals and perennials in both groups, and there are pre-emergent and post-emergent herbicides to use on these weeds. I try to avoid chemicals, as they can deplete the soil of good microorganisms and earthworms. If you use an herbicide, make sure it is one that will not kill St. Augustine or damage trees, shrubs and other desired plants. However, always spot-spray any chemical first rather than spray your entire lawn.

No doubt about it, brown patch is ugly, and I find I have less tolerance for this pest than weeds. Usually it crops up in the fall; then the grass goes dormant in cold weather. But this year, winter wasn't cold enough to subdue this perennial annoyance.

Brown patch symptoms include circular or irregular patches of blighted turf. The leaves die and pull away from the living stems. The patches range from inches to several feet in width. You'll likely note yellow leaves at the edges of the patches. These leaves look water soaked. Grass blades within the patches gradually dry out and turn brown as the circle grows.

Brown patch is especially troublesome when night temperatures drop below 68 degrees and daytime temperatures are in the 75- to 85-degree range, and when there's abundant moisture.

Organic gardeners treat the disease with a baking soda spray and practice soil health, don't overwater, improve drainage and go easy on the nitrogen. There are numerous chemical fungicides on the market.