How To Water A Lawn
Watering a lawn properly or not can mean the difference between a lush, green lawn you can be proud of or a burnt-out patch of withered up or dead grass. Certain types of lawn grasses may require a lot of water during the hotter summer months, while others may require less. Where you live, climate, and whether water is abundant or in short supply are important factors in helping you to choose the right grass type for your lawn.

Strategies for Watering a Lawn

Below you will find some strategies for watering an established lawn and/or reducing your water use while still getting good results.

Watering restrictions - First, you want to find out if your community has watering restrictions. Many communities have responded to water shortages by implementing laws that restrict how many times per week residents can water their lawns, or for how long, and/or at what times. If you live in such an area, this article can still help you.

When to water - Water only when your grass needs it and never in the late evening. Watering in the late evening or at night might leave water on the grass blades which can lead to the onset of damaging or deadly fungus and disease. For this reason, automated irrigation systems should be set to run during the early morning to early afternoon hours.

How to tell when your lawn needs water  - Your grass will tell you when it needs water. When about 30% or so of the grass blades in your lawn turn from green to bluish-grey, and older leaf blades begin to curl, it is time to water the lawn.

How much to water - Water only when your grass needs it. Keep in mind that overwatering not only waste's water but can also be bad for your lawn's health by contributing to the development of damaging fungus and disease. Watering less frequently but more deeply is recommended, however, different soil-types will absorb water at different rates. Watering deeply will encourage deep root growth. Frequent shallow waterings encourage weed germination, and they also cause the grass plants' roots to grow shallow, leaving the plant more susceptible to drought and to certain diseases. Deep watering to moisten the soil to a depth of 6-8 inches or more, if possible, is most beneficial.

You can determine how long to leave the manual or automated sprinkler(s) on by using the following method:

Turn on your sprinkler for 15 minutes. Observe whether or not there is runoff before the time is up. Then, after 18-24 hours, find out how deep the water soaked in by digging a small hole in the watered area or using a probe (a probe will push easily through damp ground). You can also push a shovel into the ground and use it as a lever to spread the soil apart enough so that you can see several inches below the surface. Once you see how deep the water went in 15 minutes, you can calculate how long you need to leave your sprinkler on to water to the necessary depth of at least 6 inches. For instance, if the soil is moistened to a depth of 3 inches from 15 minutes of watering, you would need to water your lawn for 30 minutes to achieve a 6 inch depth.Note: For clay soils that do not absorb water as readily it may be necessary to water several times for shorter periods of time to avoid runoff.

Note: You can estimate how much water you'll need based on your soil type. In general, 1" of water will penetrate sandy soils to 12", loamy soils to 6-8", and clay soils to 4-5". Using these estimates isn't quite as accurate as digging, but it's pretty close, especially if you have a good knowledge of your soil composition.

Other Lawn Watering Tips

  • The right aim. Aim your sprinklers to water the lawn, not the sidewalk or street. Slight adjustments to your sprinklers can save a lot of water.

  • Avoid creating runoff. Even with sprinklers correctly targeted at the lawn, many people water until (or even after) water begins to run off the grass and into the street or driveway. This can waste a lot of water, and it isn't doing your lawn any good. If water starts to run off your lawn before you've been able to give it a deep watering, turn off the water for 15-20 minutes to let the ground absorb the water, and then continue watering as needed (rotating a sprinkler between one area and another will also do the trick).

  • Let the rain do your work for you. Nothing looks more wasteful than running your sprinklers while it's raining. If your sprinkler system is on a timer, get and install a rain sensor that automatically turns the water off when it rains. If possible, also avoid watering if rain is expected later in the day or during the next day. Your grass should be fine, even if it looks stressed. Use a rain gauge to determine how much rain you received, and then water a bit more only if needed.

  • Consider getting a rain barrel or tank to water gardens and landscapes. A properly installed rain barrel or tank which harvests rain water from the gutters of your home provides ample water for gardens and landscape areas. Capturing this rain water reduces the amount of run off that may otherwise be picking up garbage, oils, fertilizers, pesticides and other pollutants that are on your lawn, sidewalk and street. Thus, this also reduces the amount of pollution getting into our rives, lakes, streams and ocean.

  • Water problem areas by hand. Many lawns have one or two spots that require more water than the rest of the lawn. A south-facing slope (or, in the Southern Hemisphere, a north-facing slope), or an nonshaded area in an otherwise shady lawn are two common examples of these "problem areas." If you water your entire lawn every time you need to water these hot spots, you'll likely overwater everyplace but these spots. Instead, water them by hand or use a separate sprinkler that's not attached to the rest of your irrigation system.