Water your grass deeply to develop long, healthy roots. Water until the soil is saturated to a depth of at least 6 inches. Allow the soil to dry slightly before watering again, as frequent, shallow irrigation will create shallow roots. Although water needs vary depending on the type of grass, soil type and weather, 1 1/2 inches of moisture per week is a general rule of thumb. Water in the morning so the grass has time to dry before evening, as watering late in the day can promote disease. Use a lawn sprinkler that will distribute the water evenly.
Fertilize grass up to five times per year in order to maintain a healthy, green lawn. For some lawns, one annual fertilizing in autumn may be adequate. Apply a high nitrogen fertilizer with a 3-1-2- ratio such as 18-6-12. Refer to the fertilizer container for specific guidelines and rates of application. Avoid fertilizing in early spring, which will stress the roots. Never fertilize on top of snow or frozen ground, as the fertilizer may wash off and end up in lakes or streams.
Mow your lawn to a height of about 3 inches. Mowing shorter will not only create more work, it can weaken the roots, which can make the grass more susceptible to drought. Mow your lawn when the grass reaches lengths of about 4 1/2 inches, or every one to two weeks, depending on rate of growth.
Sharpen your mower blade regularly, as a dull blade will tear the grass instead of cutting it straight across. As a result, the grass will require more water and will be more prone to disease.
Leave mower clippings when you mow, as the clippings will restore nutrients to the grass. If you cut the grass regularly, the clippings will be short and won't cause thatch. Earthworms will help the recycling process, improving the overall health of your lawn. If possible, use a mulching mower, which will leave very small clippings. Don't allow clippings to build up in gutters or on sidewalks, as the clippings, high in phosphorus, are polluting when they wash into drain systems.