Fall is a good time to evaluate your lawn care program and make adjustments for the coming year, whether you do it yourself or contract it out.

• Fertilize in the Fall. Timing is everything when you apply fertilizer. First, adopt this mantra: Fertilize in Fall, Fertilize in Fall, Fertilize in Fall. Fall is when the roots that will sustain the plants through the following summer are actively growing.
• Not in the Spring! Spring fertilizing encourages leaf growth at the expense of root development. It also feeds weed species and can lead to disease and insect problems later in the season. In addition, you will have to mow the lawn more frequently. If you must fertilize in the spring, limit it to a light feeding (half-pound of 10-10-10 per 1000 sq. ft.) after the initial flush of growth has subsided in May.
• Never Fertilize in the Summer. Most lawn grasses in our area are cool season species, which die back during the heat of the summer.
• When in the Fall? The ideal periods for application are the first two weeks in September and between the last mowing and Thanksgiving. Effective lawn feeding after Thanksgiving often is hampered by wintry conditions, during which time precipitation will wash the fertilizer into local streams, contributing to waterway pollution.
• Choosing a Lawn Care Company. If you decide to leave lawn care to the professionals, carefully research a company’s methods of operation. Does the company offer a variety of pest management approaches from which you may choose? Does it apply pesticides on a regular schedule regardless of need or does it limit pesticide use to only when needed? Does it evaluate and treat your lawn as a single entity, or does every lawn get the same treatment? Does the company routinely combine fertilizer and pesticides in each application?
• Soil Matters. Before you fertilize, test your soil to learn what, if anything, it needs. For $10.00, Virginia Cooperative Extension will analyze your soil sample and return the results to you. Pick up a soil test kit at any Fairfax County Public Library or at the Virginia Cooperative Extension office at the Government Center (Pennino Building—10th floor).
• Just Lime? If your lawn needs anything, it is likely to be lime. Most soils in northern Virginia are acidic; lime helps to neutralize the acidity. A balanced pH will improve the availability of nutrients, encourage thatch decomposition, and benefit soil microorganisms, all of which are essential to the soil’s health and fertility.
• Lime Tips. Lime can be applied to your lawn area any time of the year. However, because it takes several months to be fully incorporated into the soil, it is best to apply it in the fall. For turf, pelletized limestone is preferable to pulverized limestone. The pellets spread more evenly with less dust. The soil test results will reveal the amount of lime required to bring your soil to optimal levels.
• Keep It Sharp. Sharp mower blades produce a cleaner cut that slices through grass rather than pulling it by the roots. A sharp blade will give your lawn a more uniform appearance. In addition, sharp blades help extend the life of your mower because the engine will not have to work as hard to produce the same results.
• Cut It High... Set your blades for a mowing height that will remove only the top one-third of the grass blade. Higher settings allow the grass to compete effectively with lower growing weed species. Higher growth also shades the ground from the sun, reducing moisture requirements. If you have a small lawn, consider using a manual-reel mower. It saves energy, reduces pollution, and burns calories, too!
• ...Let It Lie. Turf clippings are mostly composed of the grass’ leaf tissue and thus decompose rapidly. Clippings left on the lawn will contribute a substantial amount of nitrogen and other nutrients to the soil, thus reducing fertilizer requirements.
• Integrated Pest Management. By using healthy lawn care practices, you will cut down the need for pest control. If you use pesticides, apply only to the area that is affected by the pest.

The Virginia Cooperative Extension offers a number of useful publications. Look for the links under Lawn & Garden on their publications page.