Lawn and Garden Care: Extension experts offer management tips for protecting plants during drought

Following a warm, dry winter with exceedingly low snowpack across the Cowboy State, Wyomingites are preparing for the possibility of widespread drought conditions this summer.

Drought poses threats to agriculture and horticulture alike, on both small and large scales.

As summer approaches with the promise of dry days ahead, Extension experts with the University of Wyoming (UW) and South Dakota State University (SDSU) offer advice on caring for lawns and gardens during drought.

Watering well

Making the most out of a limited water supply is crucial to effective lawn and garden maintenance during drought. 

First and foremost, following official water use restrictions wherever they are in place is of utmost importance, stresses UW Extension Horticulture Specialist Jennifer Thompson in a May 19 UW Ag News article. 

Thompson recommends prioritizing watering practices and planting decisions based on growing length and personal preferences.

“Prioritize which plants take the most time to grow and which you value the most,” Thompson writes, noting trees often take the most time to grow and provide large benefits including shade, energy savings, wind protection and screening. 

“Young trees which haven’t established their root systems need the most consistent watering,” Thompson explains. “Shrubs often take the next longest amount of time to grow in Wyoming landscapes, followed by perennial plants and then annuals.”

For gardeners navigating drought, Thompson emphasizes vegetable plants do not generally produce well without adequate water. With this in mind, she recommends reducing vegetable gardens to whichever plants are most enjoyed fresh and saving lesser-loved veggies for a later, wetter growing season.

Whatever the garden size, utilizing a drip irrigation system can be an efficient way of watering without promoting weed growth, according to Thompson. 

In terms of timing, watering early in the morning or late in the evening when outside temperatures are coolest and avoiding watering during rain or snow storms can help individuals get the most out of their watering schedule.

“To keep water from being lost to evaporation, water when temperatures are cooler and it is not windy,” Thompson says. “The evening or early morning hours of 6 p.m. to 10 a.m. are generally cooler and less windy.”

Absorption test

In order to make the best use of water, Thompson recommends wetting soil just to root level. She notes root depths vary based on plant type, with trees tending to have deeper water-absorbing roots than vegetables or grass.

To test absorption depth, Thompson outlines a simple test which can be performed by inserting a screwdriver into stressed soil.

“In more permanent plantings such as turf, trees and landscaped areas, you can use a screwdriver to check how deeply irrigation water has penetrated the soil,” Thompson writes.

“When you know your soil is dry, select a small area and water it for roughly 10 minutes at a rate that keeps the water from pooling or running off,” she continues. “Let it sit for half an hour, then return to the site and try to push a screwdriver at least six inches long into the soil.” 

“See how far you can push it down before you have much resistance, then try this again on a nearby patch with similar soil which has not been watered,” she adds. “If the screwdriver goes into the watered soil more easily, you can now judge approximately how deep the soil is moist with the screwdriver.”

Thompson emphasizes this test will not work for all soil types, particularly in very sandy soils where there is little resistance in both sites.

Irrigating efficiently

Regarding sprinklers and irrigation, examining water systems for signs of damage and inefficiency can help homeowners spread out their water usage effectively and prevent overwatering.

“Many lawns are overwatered,” Thompson notes. “The best step homeowners with irrigation or sprinkler systems can take to save water is to examine the system to make sure they are not overwatering.”

Water needs for turf throughout Wyoming vary by elevation and season, with one to two inches of water per week being sufficient for most lawns during the summer, according to Thompson.

Checking water lines for leaks and ensuring sprinklers are directing water toward plants rather than spraying onto sidewalks or driveways are two additional simple – yet crucial – practices to reduce water waste.

Mulch can also help retain soil moisture, and Thompson recommends incorporating mulch to as many shrubs, perennials, annuals and vegetables as possible, making sure application methods allow for water to penetrate the soil. 

Mowing practices

When it’s time to trim grass, both Thompson and SDSU Extension State Climatologist Laura Edwards recommend mowing high, with mower height set anywhere from two-and-a-half to four inches.

“Mowing high gives the lawn a deeper and larger root system, keeps moisture in, defends against weeds and keeps the soil cooler,” Edwards explains. “Mowing too short during dry conditions can injure or wear out dormant grasses to the point where they may not come back during cooler conditions.”

Thompson also recommends using a mulching mower rather than bagging grass clippings, and Edwards emphasizes the importance of keeping mower blades sharp since dull blades can damage grass leaves.

“Sharpen lawn mower blades twice a year,” Edwards recommends. “A dull blade tears at the grass, forcing it to use 40 to 60 percent more water to recover.”

In addition, Edwards reminds landscapers to never remove more than one-third of grass at a time, as any more removal can cause unnecessary stress to lawns.

Minimizing drought damage

In addition to smart watering and maintenance practices, experts also agree putting large landscaping projects on hold and delaying fertilizer applications during dry weather are essential to protecting plants and minimizing long-term damage.

“Drought is not a good time to do large landscape renovation projects, even if you are converting from high water use plants to low water use plants,” Thompson says, emphasizing almost all plants need extra water when they are first planted which is not practical during drought.

“If plants are drought stressed, do not fertilize unless you see signs of deficiency,” she adds. “Fertilizer often contains salts which can increase drought stress in plants unless they are thoroughly watered after fertilization.”

Allowing grasses to go dormant when the weather gets hot can also help preserve turf, according to Edwards.

“When conditions get too hot and dry, cool-season grasses will go dormant. Dormancy means active shoot growth will stop,” Edwards explains. “Grasses may turn brown and some may die, but the crown, rhizomes and roots are still alive.”

During this time, Edwards recommends applying just enough water to keep the turf alive – roughly one-quarter to one-half of an inch of water every two-to-four weeks – until drought conditions improve.

“Once it cools down or rain starts to fall, shoot growth will begin again and the lawn will green up,” Edwards explains.

Reducing foot traffic on drought-stressed lawns and reducing garden vegetables to the essentials are two additional simple ways to minimize potential long-term drought damage.

“Drought is a time to make the best use of the water available to us and to start thinking about changes we might want to make in the future to have
more drought-resistant landscapes,” Thompson concludes. “In the meantime, we persevere and look forward to a greener time ahead.”

Grace Skavdahl is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.