Grass species vary considerably in the amount of moisture they require, and conversely, in how well they are able to grow in wet or dry soils. Lawns need up to an inch of water per week in order to thrive. If "Mother Nature" does not provide the needed liquid nourishment for lawns then homeowners have to irrigate.
No matter your location or what type of grass you grow, at some point a homeowner will have to supplement water to their lawn. In our area we have become all too familiar with the intense hot and dry summers that we are commonly blessed with. Knowing when and how to irrigate can be deceiving, yet it is not an exact science. What is good for your neighbor's and family's lawns may not be what is needed to help your lawn flourish. Exactly when and how often to irrigate depends on several factors: your grass species, your soil type, your climate and the pattern of watering you have established in the past.
How do you know when to irrigate your lawn? If you pay close attention, the lawn will tell you. The grass blades roll up lengthwise to conserve moisture. At the same time, they lose their bright green color and the entire lawn may take on a grayish cast. Thirsty grass also loses its resiliency, so a good way to determine if you need to irrigate is if your lawn shows foot prints after you walk across it.
The water requirements for a given lawn can range from a tenth of an inch per day in a cool or shady location, to a half inch per day in the full sun, hot temperatures, high winds and low humidity. Even with the above mentioned conditions a lawn does not need to be irrigated daily. The soil under the lawn has a lot to do with how often you need to irrigate. Sandy soils do not hold water well, so a lawn grown on sand may have to be irrigated two or three times a week if it does not rain. Clay on the other hand retains water well, and a lawn on a clay soil may require watering only once a week.
A slow, deep moistening of the soil six to 12 inches in depth as infrequently as possible is a great method of irrigation. A few minutes every night of irrigating is not good for a lawn's roots. Roots grow only where there is water, and if you only wet the top couple of inches of soil the roots do not venture any deeper. By doing so you have created a weaker more delicate lawn that will require more frequent irrigation, which in turn promotes the ideal disease development conditions from the damp surface.
There are many types of sprinklers on the market, but a homeowner must be aware that different brands of the same type of sprinkler vary considerably in their precision and performance, as well as durability and ease of use.
As a homeowner you must identify a style that you are not only comfortable with, but serves its purpose. When you choose a sprinkler you must consider flow rate, throw radius and uniformity of coverage. Choose a sprinkler that offers uniform coverage. A long throw radius controls the amount of ground the water spray covers. In general, a sprinkler with a slow flow rate is best because it prevents wasteful water runoff.
WATER SAVING TIPS
Water early in the morning. Watering during the day can waste water through evaporation.
Aerate your lawn before dry weather arrives to improve its drainage and moisture-holding capacity.
Avoid over fertilizing. Excessive nitrogen causes a growth spurt so the plant requires more water.
Increase your mowing height by about a half inch. This extra height helps to shade the crowns of the plants during hot, dry weather.
Pull or spot-spray weeds to eliminate them and prevent them from competing with lawn grasses for moisture.
Marcus L. Matthews is the Department Chair and Instructor Of Horticulture at Augusta Technical College's Thomson/McDuffie Campus.