Brown Lawns are Dormant, Not Dead
Water by the clock for a greener lawn in drought
The Bay Gardener has never irrigated his lawns nor lost a lawn because of drought. When soils dry during the summer growing season, lawns become dormant. A lawn that starts turning brown should be left alone.
Unless you commit to religiously applying at least one inch of water each week in split applications one-half inch every three to four days you’ll kill your lawn by watering it only on occasions.
To keep your lawn green all summer long, water well and on a regular schedule. When using a sprinkler, place an empty tuna fish can halfway between the sprinkler and the outer boundary of its pattern. When the can is half-full, move the sprinkler to a new location. Water during the night to reduce water lost by evaporation, but make sure that the grass does not remain wet for more than 14 hours. This means waiting to water your lawn until 7pm in the evening; in the morning, don’t water until at least an hour after the dew (or the previous night’s watering) has dried from the foliage.
Semi-automatic irrigation valves are sold at many garden centers. These attach to the spigot and turn themselves off based on the setting you’ve selected. Never set the timer for less than medium. A medium setting will generally operate the sprinkler for an hour to 90 minutes.
Soaker hoses, especially those made from recycled tires, are very effective for irrigating vegetable and flower gardens. However, if the water you are using contains high levels of calcium, they can only be used for three to four years before they become clogged. Most appear to apply only an inch band of water, but capillary movement in most soils will spread that water from six to eight inches below the surface and on either side of the soaker hose. Don’t use a semi-automatic irrigation valve on your soaker hoses.
Row-drip irrigation tubing, however, is superior to soaker hoses and costs much less. Buy it from dealers who sell to farmers and nurserymen. This tool operates best with about four pounds of pressure per square inch and can be used in lengths of up to 300 feet. When properly stored, the irrigation tubes can be used for many years.
Watering your lawn with a hand-held garden hose is the worst thing you can do.
Ask Dr. Gouin your questions at firstname.lastname@example.org. All questions will appear in Bay Weekly. Please include your name and address.