The sweltering heat of summer is taking a toll, not only on our outdoor activities, but also on our landscapes. While we can find sanctuary in the shade of a large tree or the cool breeze of air conditioning, our flowers droop in the heat. The one plant to take the biggest hit is the lawn. Our lush dark green carpet seems to be turning to straw right before our eyes.
Many homeowners struggle with turfgrass in our area. Browning could potentially be caused by disease, insects, pets, mowing or fertilizers. It seems like a mystery, but in most cases, the summer browning is caused by a lack of adequate moisture.
Most homeowners in our area prefer to plant Kentucky bluegrass, fine fescue or perennial rye blends. These are considered cool-season grasses, meaning they love temperatures between 65 and 85 degrees F. Once the temperatures rise with the summer months, the turf itself would prefer to go dormant, the unsightly straw color. To avoid this, it is important that we adjust the watering time on our sprinklers to offset the amount of moisture being pulled out of the plants leaves.
How much is the right amount, and how often you adjust your sprinklers are challenging questions. There is not a clear answer, as every landscape has different exposures, soils, uses, mowing heights and fertilizer regimes, thus changing the water demand. When we experience temperatures in the high nineties and triple digits, most turf areas require at least two inches of water per week. The two inches is only for the turfgrass. If you have trees, the water need will increase, as the tree roots will grow into the turf area to access water and nutrients, even if they have their own watering system.
If your bluegrass turf seems to turn gray or faded blue between watering days, that is a sure sign it is under water stress and needs more moisture. If your turf has turned the brittle straw color, it is not dead but has gone into a self-preservation mode we call summer dormancy. The roots are still alive, but there is not enough moisture in the soil to support the plant staying green. An easy way to know if it is a water issue is to look around at the rest of the lawn. If areas that receive more shade are still green and areas that receive all-day sun are declining, water should definitely be considered.
There are several ways to check your moisture, but the best is to dig into the turf and see how dry the soil has actually become. The best time to check is the day your sprinkler system will run, but before the sprinklers come on. This will show you the stress the plant goes through between watering days. The shovel should go a minimum of six inches into the soil easily, and the soil should still be damp. If your soil is dry, it is time to adjust your water run times by adding more time or another cycle. The Washoe EvapoTranspiration Project website, https://wrcc.dri.edu/washoeEt/, can also give a starting point for sprinkler run times. The site is updated daily (except Mondays) and provides information for people who are on a three-day-per-week watering cycle.
Once the moisture is adequate for the air temperature, you should see your turf begin to regrow within a few weeks. It is also beneficial to mow at least three inches high to help your lawn make it through the summer.
Wendy Hanson Mazet is the Master Gardener coordinator for University of Nevada Cooperative Extension in Washoe County. Have questions about your lawn? Contact a Master Gardener at firstname.lastname@example.org or 775-336-0265.