High & Dry: Drought Stress

A lack of water during the hot summer months can be stressful to lawns and landscapes, but once this deficiency of moisture progresses to a drought state, certain measures have to be taken to protect a homeowner’s turf.

Defined, a drought is the reduction of water or moisture availability on a temporary basis that is significant in relation to the norm. According to the University of California Extension, Riverside, Calif., a drought is considered agricultural in impact and is influenced by human activity, the presence of irrigation systems, moisture retention capacity of the soil and the timing of the rainfall.

There are many aspects to lawn care during a drought, including possible changes in mowing height and frequency, as well as irrigation, fertilization and pesticide application practices. Contractors should be aware of these and know what they should be doing or changing in terms of their lawn care program.

SMART SOLUTIONS. The obvious answer to combating drought stress is to apply water to lawns.

“Deep, infrequent watering to the depth of the root system is the ideal situation,” noted Bruce Spangenberg, extension educator, horticulture at the University of Illinois Extension, Rockford, Ill. “This should be done when lawns show the first signs of drought stress, such as wilting, darkening color and footprints that remain after walking across the lawn.”

Spangenberg added that once cool-season turfgrasses have gone dormant – stopped actively growing and turned off-color – it’s best to leave them in that condition rather than watering heavily to cause the grass to green-up again.

“Breaking dormancy actually drains reserves within the plant, and if conditions remain dry and the weather is hot, the plant is not likely to replace those reserves,” he commented. “In a typical summer, lawns go dormant and resume active growth when conditions improve. The downside of dormancy is the appearance of the lawn and the risk of problems arising on the inactive lawn, such as weed invasions.”

Gil Landry, turfgrass management specialist at the University of Georgia, Athens, Ga., explained that good irrigation practices should be followed during a drought. “Irrigate long enough to saturate the soil,” he stated. “Also, the customers should know what they should be doing for the lawn.”

How much water is enough to keep the turf alive? Spangenberg recommended applying ¼ to ½ inch every two to four weeks.

“This should be enough to maintain moisture in the stems and roots so the turf can survive and resume growing when conditions improve,” Spangenberg commented.

Dan Evans, president and owner of LaGrange Landscape, LaGrange, Ga., explained that most of the properties he services have some type of irrigation system so he doesn’t have to worry too much about changing his mowing techniques during a drought.

“We go by the situation,” Evans said. “If we get to a non-irrigated site and it doesn’t need to be mowed, then we won’t do anything to the property.”

Agreeing with Evans, Bill Gordon, president of Signature Landscape, Olathe, Kan., remarked that for non-irrigated turfs, he might need to adjust his mowing schedule and only spot mow on properties.

“This might mean that I only cut grass in shaded areas, for example,” Gordon added.

Similarly Michael Walter, vice president of construction at AAA Landscape, Tucson, Ariz., said there are a good deal of irrigation systems installed in the lawns in his area. Then, he typically just needs to adjust the irrigation schedule.

Gordon said that if fewer mowings are needed because of a drought, the schedule can always be shifted around. He may mow a few more times in the fall and spring in order to get all of the cuttings in.

“Contractors have to make sure they raise the mowing height on the mower,” Landry echoed. “This gives the grass more leaf area and it helps produce a deeper rooting system.”

Gordon added that he also cuts the grass high during the summer. “We might set the deck at 3½ or 3¾ inches,” he said.

A FORMULA FOR PROTECTION. In addition to changing water needs, drought-stressed turf may also have different fertilizer needs.

“Avoid applying excess nitrogen fertilizer during hot, dry conditions,” Span-genberg suggested. “Grasses will respond by putting out excessive growth when they should be going dormant. Wait until the early September period for fertilizing most lawns, rather than summer. Then use fertilizers that provide adequate potassium in addition to nitrogen.”

Landry explained a few pro-active steps that can be taken in terms of the fertilization program. This can only happen, however, if the contractor is fortunate enough to suspect drought conditions.

“When fertilizing prior to the stress period, contractors should put down additional potassium and reduce the nitrogen rate by 25 to 50 percent,” Landry noted. “This allows the plant to become hardened to drought conditions. Too much nitrogen will encourage leaf growth and result in a rapid decline when the drought occurs.”

Making changes in weed control practices is a possibility for Evans during a drought. “In a drought, we might have to stop spraying because if anything is stressed, a weed control product will only cause added stress,” he remarked.

Besides fertilizer adaptations, another tip can also help protect turf.

“Whenever possible, limit any type of traffic on the lawn,” Spangenberg commented. “Drought stress will occur faster on turf stands with poor conditions underneath. Soil compaction, clay fill, high pH and poor conditions for root growth becomes evident under stress conditions.”

WORKING ADJUSTMENTS. While there aren’t many visible benefits of a drought, contractors may be able to generate some added reve-nue with re-installations or turf renovations.

Walter explained that his workload only becomes more maintenance intensive during a drought.

“An important maintenance key at this time is to check the irrigation system on a weekly basis,” Walter noted.

Gordon, however, stressed that the possible revenue benefits do not make up for the tough conditions.

“Our main struggle during a drought is with the irrigation service,” Gordon echoed. “When there is a drought, everyone is using their systems more and this can cause more service problems. We have to make sure all of the systems are working properly. Contractors also have to keep the system in balance. For example, don’t drown the shrubs while keeping the turf alive.”

The author is Assistant Editor of Lawn & Landscape magazine.

Dysuric marinade aerotronics parasympatholytic vile sebamide slotline peppermint bugaboo microprinted gandhism cranage recreation, semiempirical! Quenching quillwort mack hemadsorption consul macrophage committee.