April's Lawn Pest: Drought Stress
Posted April 3, 2017 by Rusty
Although the word 'pest' is typically used to describe an insect such as chinch bugs or webworms, the term is actually used to describe anything that is unwanted. (Perhaps you remember what you may have called your little sibling growing up?) In this case, a lawn certainly is not improved by being pestered with a lack of one of it's three basic needs)
When and where is drought stress the most prevalent?
Imagine filling a gallon bucket with water and setting it out in your yard. When you check your bucket a week later, you’re going to find it still has water, but you’ve lost an inch or so from evaporation. That’s what happens to your lawn and landscape plants if the evaporation isn’t replaced by rain and/or irrigation. If you had the bucket of water in full sun, it would experience more evaporation than one in the shade. Also, a bucket put out in summer would lose more to evaporation than one in winter.
All of that is to explain that drought stress is most prevalent in the sunny areas of your lawn and in the driest times of the year.
How can I identify this as the problem in my lawn or landscape?
St. Augustine and Zoysia lawns are the easiest to diagnose drought stress in. Both leaves have a midvein that acts as a “spine” for each individual blade, allowing it to open and close as needed. Healthy, well-watered grass blades will appear almost completely flat and totally open. When grass begins to dry out, the blade will close in half upon itself, to reduce its surface area to the sun and thus conserve water. This will also give the grass a “hazy” look, as the backs of the blades are not as deep a green as the enclosed fronts.
How does it occur and how can I prevent it?
As mentioned above, drought stress is simply a lack of water, which is one of a lawn's 3 most basic needs.
What can I do to resolve the issue?
Turn up your irrigation settings (link is a tutorial on Gainesville Irrigation settings). When I advise this, the typical response is, “But there’s an irrigation rule that says I can only water 2 days per week.” That’s completely correct. However, the frequency of the irrigation running typically isn’t the problem. Most of the time, I find irrigation timers set to run anywhere from 15-20 minutes per zone - and we recommend anywhere from 30 to 75 minutes per zone.