Turfgrass Spring Blog #2: 2019 Edition
Clint Waltz, Ph.D. –University of Georgia Turfgrass Specialist
To date, the average 4-inch soil temperature for the entire month of April in Griffin, GA (which is fairly central for the state) is 64.1 F. In the last fourteen days, there were five days where the average daily 4-inch soil temperature was below 65 F. In general this is warm enough to get green growth, but it is barely warm enough to stimulate root growth or initiate new growth from rhizomes buried within the upper couple inches of the soil for bermudagrass and zoysiagrass.
Understanding the growth characteristics of our warm-season species and overlaying the recent environmental factors, it is not surprising some grasses appear green while others seem slow. The “slower” grasses, or locations within the landscape, could have other influences delaying green-up.
If the area is on the north side of a building, in a low area that retains more water, a wet spot in the landscape, shaded, further north of Griffin, GA, etc., it may be a little slower to green-up. Water is a good buffer of heat, meaning it takes more energy (the sun’s energy) to warm the soil to the same temperature than if the soil was dry. Wet areas will green-up more slowly than dryer areas.
Considering the amount of rain the state has received since last summer, all of our soils likely have good, to excellent, moisture content. Also, a thin area may be slower to cover, or appear green, because the soil temperatures for initiating new shoots from rhizomes will take more time – it takes time for warmth to move through the soil and trigger new growth, then it takes time for the new shoot to reach the soil surface.
Warm-season grasses have changed substantially over the past two to three weeks, and a favorable environmental is just now becoming conducive for active growth. Likewise, the next two to three weeks should encourage growth and green-up.
“Patience is a virtue” and a little green grass seems to cause us to be less virtuous. Be patient and stay with the program, our warm-season species should be growing strong shortly.