The dry weather has returned, or so it seems for now. As we enter tropical storm season it remains to be seen just how much rain we will get. It is often droughty in Georgia, but especially here in coastal GA where our sandy soils typically drain quite well. We’ve gone from droughts (last summer) to floods (this past winter) and weather extremes like these stress plants. What can we do to get the most from our sprinklers? Here are a few questions and concerns I’ve been fielding in the office of late, I hope they can help direct you.
Why does my grass look grey/brown? Even if you recently watered lawn grasses can turn grey and the leaves roll up when the lawn is dry. After you walk on a dry lawn, your foot prints will remain for quite a while.
Do not assume that just because you watered or because the spot is close to a sprinkler, that the area is getting water. Put a pie pan or empty tuna can in the affected spot and put one in a good area. Run the sprinkler system through one complete cycle. Each area should receive from one-half to three-quarter inch of water. Does the affected area receive this much water? Does the affected area receive as much water as the good area? If not, adjust your system so the area receives at least this much water every time. Wait until the lawn begins to turn grey to water again.
Well, I did this and still have a problem! Check the soil in that area. Is the soil hard and compacted? To check soil compaction, water the area well. Push a rod or wire into the soil. If you cannot push the wire to a depth of 6 to 8 inches, soil compaction is probably a problem.
Hard soils prevent water infiltration and contribute to shallow roots and droughty turf. The best solution is to till the area and then replant. Core aeration will also help but must be done properly and regularly. Use an aerator that pulls cores out of the ground. Cover 15 to 20 % of the soil surface with holes. Leave the holes open, do not fill them with soil. Core aerate through June and again next March through June. Remember that core aeration generally only penetrates up to three inches deep.
My problem cannot be water. I water every day! (Or every other day). If you do this - then most likely you are watering too often and too little each time. Lawns like infrequent but deep watering. Water to wet the soils 6 to 8 inches deep each time. This will probably require one-half to three-quarters inch of water each time. Then wait until the lawn asks for water (by turning grey) before watering again.
The length of time between watering is determined by the drought tolerance of the turf type, the condition of the lawn, the soil type and other factors. In general, a good quality established lawn should have to be watered every 5 to 11 days. I would certainly try to never water established lawns more often than twice a week. The most drought tolerant grass is Bermuda grass. Zoysia is second in drought tolerance. They should be able to go longer between waterings than the less drought tolerant turf grasses like centipede and St. Augustine.
If you are watering too often, slowly wean the turf from this program. Begin to water less often
but longer each time. Your goal is to water one-half to three-quarters inch each time and then wait until the lawn asks for more water. When the roots are allowed to grow down searching for moisture in the soil you have deeper healthier root systems less likely to be easily impacted by environmental, insect, or a fungal pathogen.
How do I determine if I have an irrigation system problem? I would suggest you conduct an irrigation audit. Set a series of low cups in a row from one sprinkler head to another. Put them several feet apart. Run the sprinkler through one complete cycle. Look at the amount of water in each cup. Are you putting out enough water? Is the distribution even? Do you have overly dry or wet areas? Adjust your sprinkler or get a professional to help you to adjust the system so that you get enough water (but not too much) in each area.
Water is precious, especially in a drought. Making the most of the water you use saves money, conserves water and produces a healthier lawn. Use these tips to make your landscaping more water efficient and productive.