The number one thing I find most customers know little about is how to properly water their lawns. Some water every day for 20 minutes, some water every day for 10 minutes at a time, 2 times a day and the list goes on. There is so much confusion on the subject because frankly there is no one proper way to water your grass! In simple terms, your lawn needs about 1”-1 ½ ” of water per week. Water less in the spring and fall when we have cooler, less stressful temperatures.
How you get water into the rootzone is the important key. I see multiple postings online saying water ½” multiple times a week till you get to 1 ½” total. The problem with this technique is the water never gets down past the top 3” of the soil. The roots of your grass tend to stay in this area. Why spend the energy to dig deeper when the water is right there. Jump to mid-summer and we are having a heat wave where the top 3-4” of the soil gets to 90 degrees or above. Cool-season turfgrass roots like the temperature at 60-75 degrees. Once the temperature goes above this, the roots stop functioning properly; they stop pulling in water and nutrients for the leaves and the plants begin to wilt. Boom your lawn just went dormant and turned brown.
If you water for 45 minutes to 1 hour per zone, but only every 3rd day, the water would certainly get several inches deeper into the soil profile. The deeper the water, the deeper your roots will grow. By the time you get to mid-summer and deal with its heat waves, the top 3-4” of the soil is 90 degrees, but about 6” down it’s a cool 75 degrees. The roots down there are sending water and nutrients up to the leaves. The grass may be stressed but it’s still growing and green. The actual amount of time you will need to water each area will vary for many reasons. How much water does your sprinkler supply per hour? Do you have sandy or clay-type soil?
Hard and fast general rules for watering are:
- Mimic Mother Nature by watering longer and less frequently. Your roots will go deeper and you will reduce heat and drought stress during the summer heat.
- Allow your lawn to dry down a few days between waterings. This tells the grass plants to dig deeper and mine for water. It also causes the leaves to harden off, and become less lush, increasing the plants’ natural heat and drought defenses.
- Try to water your lawn from sunrise to mid-morning or late afternoon with the last watering ending 2-3 hours before sunset. Never water at night or at sunset. You do not want the grass wet going into the night. This is a recipe for fungal diseases. If you have so many zones it is impossible to water all your lawn during one time period, break it up. Water part in the AM and part in the PM or split the areas into different days.
- During a heat wave, it is perfectly fine to water more often for short periods of time to help reduce heat stress. On the dry, down days, I recommend running the sprinklers late afternoon for about 10-15 minutes. This is called syringing the grass. It cools the leaves and the upper soil, greatly reducing heat stress.
- In spring and fall, only water 1 to 2 times per week depending on your soil’s water-holding ability and weather. In summer, increase to 2-3 times per week with at least 1 day between deep waterings.
- The last tip isn’t a watering technique. Raise your height of cut in the summer to increase the plants’ ability to fight stress and skip mowing during heat waves unless you have to.
After a season of watering this way, you will have increased the depth of your root system and your lawn will have the ability to fight through the heat.
Jeremy Brown, Holyoke Location Manager