OTC landscape expert offers tips during heatwave

By Steve Koehler

While the Ozarks’ summer heat has eased a bit this week, July and August hold the promise of a return to high temperatures and a hot sun which can damage lawns, plants and other vegetation.
 
Danelle Maxwell, Turf and Landscape Management instructor at OTC, said proper mowing and watering of lawns and plants can help stave off the devastating effects of a summer heat wave.

 “Watering during the early morning hours of between 6 a.m. and 8 a.m. will help increase water efficiency and crease disease potential,” Maxwell said.

Watering requirements vary according to grass type. Perennial ryegrass needs about 1.5 inches a week while Zoysia or Bermuda grass only need about a half-inch a week.

In addition to water, Maxwell said lawns that are mowed too short can’t tolerate the heat and lack of moisture as well as those lawns that are kept a little longer.

Maxwell suggests the following guidelines for lawn and plant care:

• Mow grass as tall and frequently as possible with sharp blades.  Most lawns should be 3-4 inches in height after mowing, and not less than 2.5 inches. Taller grass encourages deeper roots.  Scalped turf and very shortly mowed lawns have very shallow root systems that do not tolerate heat and drought as well.

• Never cut off more than 1/3 of the grass blade when mowing.  This stresses the turf and encourages disease and pest problems.

• Fertilize correctly.  Do not apply nitrogen to cool-season grasses during the summer. Test a soil sample to determine if other nutrients are necessary.

• Control thatch in the spring and fall to encourage water and air movement into the soil.  Do not control thatch on cool season grasses during the late spring or summer, as it increases the need for irrigation.

For trees and shrubs, a lot depends on how much the root system has been established, Maxwell said. New plantings need more water during the first year, with plant species, size, and soil conditions determining specific amounts.

Here are some tips to help with watering trees and shrubs:

• Keep the root ball moist on newly planted trees and shrubs.

• Mature trees usually tolerate short periods of drought fairly well.  They have developed a larger root system, extending at least 2 to 3 times the diameter of the drip line. Judicious watering of valuable trees with a soaker hose may be necessary during extreme droughts.

•Apply mulch.  Organic mulch will reduce water evaporation from the soil, reduce soil temperature, and help to control weeds that compete for water.

• Remove weeds to reduce competition from the desirable plants.

Steve Koehler is corrdinator of publications at Ozarks Technical Community College.