Unless we are extremely fortunate, Mother Nature will not provide us enough moisture during the growing season to maintain a lush, green lawn. There are always going to be periods of hot, dry weather during the summer and lawns that are not properly watered during these times will become drought stressed.

How Much is Enough

Most grass plants see their roots reach a depth of 4-6 inches, therefore soil should remain moist to this depth. Soil composition is the biggest factor when determining how much water is required to achieve this. Although it will vary from lawn to lawn, a good general rule to follow is loam and clay soils require 1-1 ½ inches of water per watering, while sandy soil requires ½ to ¾ of an inch of water to moisten to the same depth. Soils differ in the length of time it takes to achieve these moisture levels. Clay soil is very compacted and water takes a long time to penetrate. Sandy soils on the other hand are very loosely compacted and require very little time to achieve the same desired depth.

When to Water

The time of day the lawn is watered is very important. Even though watering the lawn is beneficial, doing so at the wrong time of day can do more harm than good. Mornings are the best time to water. The soil has the chance to absorb the water before the sun becomes too hot and evaporation occurs. Also, the surface will dry quick enough to prevent diseases from developing. Evenings would be the next best time to water if mornings are inconvenient. One disadvantage to watering in the evening is the leaf blade has a very good chance of remaining wet throughout the night. Given the right conditions, this can lead to diseases such as Red Thread or Leaf Spot. Watering during the day is the least recommended time to water. Most of the water put down is lost to evaporation and the droplets can potentially act as a magnifying glass and cause damage to the leaf blade.

Tips

Most lawns require 1-2 inches of water per week during the growing season, depending on local weather conditions. Hot, dry, windy weather creates the need for greater amounts of moisture in the lawn. Having an excessive thatch layer will trap much of the moisture applied. Aeration will improve water transfer to the root system. Trees will also compete aggressively for water. These areas require much more moisture than other areas of the lawn.

Deep root watering (one inch once a week) is recommended over frequent shallow, short watering. Deep root watering entices the roots to look deep in the soil for moisture, thus becoming protected from the heat of the sun in the summer. Frequent, shallow watering forces the roots to look to the surface for their moisture, creating a shallow root zone, and one that is not protected from the hot sun in the summer time.

Gradually lessen your watering schedule as fall approaches. This tells your lawn to "harden off" and prepare for winter. Watering up till the first heavy frost will freeze the leaf blades causing massive damage to the cell structure of the plant. This will cause many problems come springtime.

For more information, call the professionals at Ace of Blades at 818-LAWN (818-5296),
or e-mail us at paul@aceofblades.ca.