Though lawns use a large portion of our water, fertilizer and time resources, we Americans seem to be married to the concept of the lush, green expanse. For those in areas prone to drought, alternatives to the traditional lawn should be considered...for those of us who, so far, have sufficient water, it still makes good sense to conserve as much of our resources as possible. The following are strategies designed to grow a successful lawn with minimal toxicity and resource use.
Keep the grass healthy by cutting with a sharp blade - dull blades tear and open the grass to disease organisms. Leave clippings on the lawn - they will supply at least a third of the yearly nitrogen requirement as well as building the health of the soil with beneficial organic matter. Mulching mowers are fairly efficient, especially if the turf is completely dry. Unless you're practicing your golf game on the lawn, there's no reason to cut the grass short. Taller grass has more leaf area for absorbing the sun's energy, is able to compete with weeds better than short grass, and develops deeper root systems which are more drought tolerant. It's important to cut no more than one third of the grass blade at each mowing - this may mean cutting more than every seven days during the spring surge growth.
Lawn grasses require three to four pounds of nitrogen per 1,000 square feet per year...clippings left on the lawn can supply up to two pounds per year and a yearly topdressing with compost can add another pound of nitrogen along with the beneficial organic matter. In many cases, commercial synthetic fertilizers are not necessary! Nature abhors a monoculture - that is, nature will always be trying to grow weeds in your lawn. By mowing high, 2.5 to 3 inches, many weeds will be suppressed by the grass. Persistent weeds can be removed with one of several types of extraction tools. Turf scientists discovered several years ago that corn gluten meal killed many weed seeds as they sprouted; applied in early spring and late summer, it will control dandelion, clover and many other lawn weeds. Use only on established lawns, since it also will kill grass seedlings. An additional benefit is its nitrogen content - an organic weed 'n feed!
Irrigation should be supplied to the lawn only when needed - excessive irrigation can lead to diseased turf and increased weed presence. Supply water as deeply and infrequently as possible...frequent, light irrigation encourages shallow rooting and poor drought tolerance.
Run an irrigation system early in the morning. This is when water pressure is typically at its best. It is also best for the lawn. If you water in the evening the blades of grass will stay wet much longer and make it easier for fungus to grow. Early morning also has the least wind. Wind can easily blow a spray pattern several feet off target resulting in dry areas.