A healthy lawn makes a very good filter for absorbing many things that can be washed into our streams, rivers and lakes. The ideal lawn is one that will grow best in your environment without lots of supplemental watering. We have all probably read about people living in desert areas trying to grow lawns that require almost daily watering just to survive the summer heat. This is extremely foolish and shortsighted. Turfgrasses were never intended to grow everywhere. However, there are parts of the country where various turfgrasses grow well without the need for daily watering. In many places, grass can be grown without any supplemental watering, or only very minor supplemental watering. The following information is specifically intended for those areas.

How much water does a lawn need?

In general, turfgrasses need about 3/4”–1” of water per week to maintain green color and active growth. However, during certain times in the summer when high temperatures are the norm, you should allow lawns to naturally slow down in growth during those extreme conditions. You may let the lawn go almost completely dormant in hot weather. Many factors, such as the soil and weather, have a role in the lawn’s water needs. Here are a few guidelines to follow:

  • Decide beforehand. Before summer heat and drought conditions arrive, to either water lawns consistently as needed throughout the season, or let lawns go dormant as conditions turn hot and dry. Do not rotate back and forth. In other words, don’t let the grass turn totally brown, then apply enough water to green it up, then let the grass go dormant again. Breaking the lawns dormancy actually drains large amounts of food reserves from the plant.
  • When is it time to water? The first few warm days of summer does not automatically mean lawns should be watered. In fact, allowing lawns to start to go under mild drought stress actually increases rooting. Watch for footprints remaining on the lawn after walking across it (instead of leaf blades bouncing back up). Grasses also tend to turn darker in color as they go under drought stress. Sampling the root zone soil could be another option.
  • Water as infrequently as possible. Thoroughly water (when you do water) so moisture soaks down to the roots. Exceptions to this general rule would be for newly seeded lawns where the surface needs to stay moist, newly sodded lawns that have not yet rooted into the soil, or when summer patch disease is a problem. Otherwise, avoid frequent watering as it promotes shallower root systems and weeds (e.g., crabgrass).
  • Water early in the day if possible. Given a choice, water early in the day when lawns are normally wet from dew. Avoid watering at midday as it leads to excessive evaporation, and avoid watering at night as it leads to increasing the potential of some diseases gaining a foothold. The exception to this guide is when your area is experiencing extremely hot weather and nighttime temperatures don’t fall below 68 degrees, then it is better to water in late afternoon or early evening providing you don’t have watering-time restrictions. Watering early or late in the day reduces the amount of evaporation that takes place during the very hot day, allowing more water to reach the root zone.
  • Spread the water uniformly across the lawn. Sprinklers vary in distribution patterns and require spray overlap for uniform coverage. Place coffee cans or similar straight-sided containers on the lawn to help measure water application rates. Avoid flooding areas or missing other spots. On heavy clay soils and slopes, watch for excessive runoff; it may be necessary to apply the water in several applications to allow for adequate penetration.
  • Water conservation. To help conserve water: mow your lawn at a higher than normal height; avoid applying an excess of nitrogen as warm weather approaches; limit traffic over the lawn; improve turf rooting; control thatch and soil compaction; and avoid pesticide use on drought-stressed lawns. Don’t allow water to hit the driveway or go into the street; it's wasteful.
  • Avoid overwatering. Use a rain gauge to measure how much water you’re applying. Overwatering does more than deplete the water supply; it also makes plants prone to pests and adds to storm water runoff, which pollutes our water systems. By choosing and operating a watering system correctly, you can reduce water bills, insect and disease problems, and maintenance requirements. For example, the more you water your lawn, the faster it grows and the more it needs to be mowed.
  • Monitor rainfall. Don’t water the lawn if rains are expected soon. Keep track of rainfall for the week. Don’t apply more water to the lawn than what is absolutely necessary. The guide of about 1” of water per week is only a guide. If your lawn doesn’t get that 1” of water, it’s not going to die.
  • Make a deep impression: water right. Every living thing needs water to survive. Your lawn is no exception. As the weather heats up, your lawn processes more and more water. Unfortunately, at the same time that the lawn is using more water through the summer, there’s usually less natural rainfall available. Without a helping hand in the form of extra sprinkling, your lawn may go dormant or suffer serious thinning. Dragging that hose around or turning on the irrigation system is one of the most important things you can do to ensure a healthy and green lawn.

The essential things to remember about watering:

  • Turf uses up much more water in hot weather.
  • Turf needs water to clean the air, produce oxygen and produce food.
  • Adjust your watering to your soil type.
  • Soaking the lawn to a depth of 6” forces the lawn to produce deeper roots.

Have questions about watering?

Contact NutriGreen — your local fertilization & weed control experts.