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Worried this drought season that your lawn is dead? You are not alone, but your worries may be unfounded. Grass is an amazing, resilient plant. There are literally hundreds of varieties of grasses, each with its own specific characteristics and suitability for various climate and soil conditions. They can be found in very cold and very hot environments all over the world and they have built-in defenses for survival when water gets scarce.
Lawn or turf grasses come in two different broad categories, cool-season and warm season. This categorization is based on the typical climate zones most suitable for their successful growth. Northern Utah falls under a transition zone so both categories of grass will grow in this climate, but each has some characteristics that you should know about to be successful.
Warm-season grasses
Warm-season grasses are not commonly used in northern Utah as turf grass, but they do grow well here and use much less water than the cool season varieties. The downside to this group is that they don't green up in spring until nighttime temperatures reach the high 40-degree range and then go dormant quickly in the fall when temperatures drop. They also have a different shade of green, a lighter, blue-green look that some people don't prefer.
Many of the warm season grasses are short prairie grasses and can be left un-mowed for the whole summer and might grow less than 12 inches in height. When they are dormant, they do not compete with the early or late season weeds so a good weed control program must be used during the dormant times. As far as water use, a well-established warm-season grass may only need water every 7-10 days in the heat of the summer in average loamy soil. They are great for water conservation, even though they do have traits that cause many to hesitate to use them.
Cool-season grasses
Cool-season grasses are the most common for northern Utah and include Kentucky Bluegrasses, fescues, and ryes. They do their best and thrive in cooler temperatures between April to June and then again from September to November. In the heat of the summer, people force these cool-season grasses to stay green and active by regular irrigation and extra fertilization. These grasses will naturally go dormant when it is too hot or too cold, however, some varieties keep a little green foliage even in the coldest months of the winter if there is snow cover.
In a typical summer with hot, dry conditions, cool-season grasses naturally want to go dormant, which means they slow their growth and the foliage turns yellow and will dry out. When conditions are suitable, they will grow from the crown and green up as they recover to full activity and active growth again. With prolonged periods without any water, these grasses can be killed. However, with as little as 1 inch of water per month, the lawn but will not typically die even if it doesn't look great. This ability to go dormant is a physiological mechanism that keeps these grasses growing naturally in many places of the world where only natural precipitation is available and droughts are common.
With the current extreme drought conditions in Utah, if you have lawn and you notice it turning yellow or straw-colored, this is a sign that it is in stress and turning dormant because of heat and lack of water. Dormancy is completely reversible, and your lawn will green up when temperatures come back down to their preferred range and water becomes available, which usually happens in September for northern Utah. You should irrigate these grasses at least once a month to keep the crown and roots alive, but don't worry if it isn't greening up in hot and dry conditions. it will green up when the conditions are right.
How do you know if your grass is dormant or dead?
First, remember that dormant grass only needs about a half-inch of water a month to keep the roots and crown alive. Second, pull on the grass blades and try pulling up the plant. If it takes effort, the plant is alive and will come back. If the grass pulls out with no resistance and it seems to pull the roots with it, it could be dead but there may likely be other problems like grubs, mold, or other pathogens that are sometimes more prominent when lawns are stressed.
Cool-season grasses can die, but for the most part in our climate, they simply enter dormancy during periods of drought and heat. If a patch ends up dying, it is generally the easiest and cheapest area of the landscape to replant. That's why lawn watering becomes the first area that is emphasized and decreased during a drought. If you must prioritize watering, prioritize trees and shrubs first with lawn being the lowest priority. Do hand-watering or use drip irrigation for the trees and shrubs rather than using your sprinkler system. It will be more efficient and get water only where it is needed to keep your more expensive plants alive.
Consider for a moment the grasses you see in nature. Of course, these are not manicured and cut every week like your lawn, but if you notice, they are green in the spring, then they begin to go brown by mid-June (depending on the temperatures) and they remain brown the rest of the season until fall rains come. But every year the grasses are back, green, and full just like the year before.
Lawn grasses are not quite that hardy because people cut and treat them differently, but they are tougher than they get credit for. Your lawn will not die because you missed one irrigation event or because it started going dormant and brown. Not all varieties are the same, but Kentucky Bluegrass, the predominant type used locally, can be quite hardy and tolerant of extended drought conditions when treated properly.
Leaving grass a little taller results in deeper root systems which make for more drought tolerance. Watering less frequently so that roots are forced deeper for water makes them more drought tolerant. And understanding how they grow and what they need can allow lawn owners to not expect lush, deep green in the summer when these grasses naturally want to slow down. They can be green and healthy in the summer but maybe not the deep, dark green we sometimes expect.
This drought is certainly one for the record books, but lawns are most likely to make it through it even though they don't look good now and won't look good through the summer. Following drought restriction recommendations will not create the lush, green appearance but it will keep it alive.
Do your part to help conserve
Everyone must do their part to ensure the water supply can last and sustain us during this time. Cutting back on lawn watering will save a lot of water. The restrictions in place may be a challenge for some but there are no exceptions on the number of days per week to irrigate. All water users are being asked to only water their lawns twice per week and only water each sprinkler zone or valve for no more than 20 minutes for fixed spray pattern sprinkler heads or 40 minutes for rotor, impact, or other rotary-type sprinkler heads.
A fixed-spray type head is one that allows water to spray out in a specific pattern. There is no rotation or movement of the head that alters the spray pattern. Rotor, impact, or rotary heads and nozzles create a stream of water from the head that rotates or moves across the area being irrigated. If you are using drip irrigation, there are no specific restrictions in place or time of day restrictions, but a reduction in frequency is encouraged. The overall purpose for restrictions is to reduce the total volume used in landscape irrigation because our reservoir storage volume is so low. For more information on the drought conditions, restrictions, or water levels, visit www.weberbasin.com/drought.
As you evaluate water use on your yard, consider what you use your lawn for and the needs or wants it provides. Do you use it for recreation, for pets, for kids or simply because it is green and generally simple to maintain? Is it only used as a decorative border around your flower beds or a pathway on a side yard? Taking stock of your outdoor needs and planning for a modification or redesign of your landscape can create a long-term reduction of water use whether the area is in drought or not. Lawn certainly has a space in our landscapes, but maybe lawn doesn't need to be the default groundcover, using a lot of water without much of a specific function.
A program designed for Utah landscapes called Localscapes can help you to design or redesign your landscape to meet your functional needs, keep aesthetic appeal, and use much less water if planned and irrigated correctly, while still using lawn as the central open shape of any yard. Using a Localscape plan can help you design a yard which fulfills your needs and wants while fitting our local climate, soil types, and designing for drought resiliency.
Visit www.weberbasin.com/conservation/classcalendar to sign up for landscape classes through Weber Basin Water Conservancy District. Look through recordings of past classes to supplement your design and visit their Learning Garden in Layton at 2837 East Highway 193 to get ideas of what a Localscape looks like.
