Watering Lawns the Right Way!

How much water does a lawn need? In general warm-season grasses need about one to 1.5 inches of water per week to maintain green color and active growth, and naturally slow down in growth and may go dormant in hot weather. Factors, such as the soil, weather, and management practices all have a role in water needs of lawns. Here are a few general rules to follow:

Decide before summer to either water lawns consistently as needed throughout the season, or let lawns go dormant as conditions turn warm and dry. Do not rotate back and forth. In other words, don’t let the grass turn totally brown, apply enough water to green it up, and then let the grass go dormant again, as breaking 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 to water lawns. In fact, allowing lawns to start to go under mild drought stress actually increases rooting. Watch for foot printing, or 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 soils could be another option.

In general, water as infrequently as possible. Water thoroughly so moisture gets down to the depth of 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 of the site, or when summer patch disease is a problem. Otherwise, avoid frequent watering that promotes shallower root systems and weeds (e.g., crabgrass)

Given a choice, water early in the day when lawns are normally wet from dew. Avoid midday due to evaporation and at night due to potential increased chances of some disease.

Spread the water uniformly across the lawn. Sprinklers vary in distribution patterns, and require spray overlap for uniform coverage. Placing coffee cans or similar straight-sided containers on the lawn can 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 two application to assure it soaks in.

To help conserve water use, mow higher, avoid excess 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.