Warmer weather and recent rains have enhanced fire ant activity with more mounds becoming visible in our lawns. Not only are the mounds unsightly but the sting from fire ants are extremely painful and for some people even life threatening.
Therefore, controlling fire ants should be as much a part of your lawn management activities as mowing, watering, and fertilizing. There are several methods of controlling fire ants but baits are probably the most convenient and easiest products for homeowners to apply. They also are effective in controlling tiny new mounds that we might overlook hidden in the turf canopy.
Adhering to a few application tips will ensure the most effective use of bait. 1. Don’t apply too much. The rate for most bait is only one to two pounds per acre. 2. Use fresh bait. Ants are not attracted to old bait that has gone rancid. 3. Since fire ants forage for their food apply bait by broadcasting it over the entire lawn and not just on top of mounds. 4. Avoid applying bait just before rainfall and do not irrigate for at least two days after applying. 5. Be patient as bait is slow-acting. 6. Apply fire ant bait preventively. Don’t wait till you see large mounds. By the time mounds are visible several smaller unseen colonies are being established. 7. Apply bait up to three times per year, spring, summer, and fall for season long control. 8. Eliminate mounds the bait misses with additional individual mound treatments.
Mowing is the one activity that we perform on our lawn more than anything else, yet it is most often done with lack of attention to cutting height, regularity, leaf wetness, or sharpness of blade. Any of these factors could cause undue turf stress and provide less than desired results.
Every turf species has an optimum mowing height and any extremes from this could cause scalping, turf thinning, and even loss of the lawn. Shade intolerant species like bermudagrass, when maintained at a mowing height greater than two inches, will begin to drop lower leaves from shading by the canopy. This often creates a scalped appearance just after mowing when the top canopy is removed and exposes the brown leafless stolons.
In contrast, a St. Augustine lawn cut less than two inches in height may become wear stressed and lose turf density due to exposed stolons and reduced leaf area. Cutting heights for our warm season turf species should be within the following ranges: bermudagrass 0.5-1.5 inches; zoysia 1.0-2.0; carpetgrass 1.5-2.0 inches; centipede 1.5-2.0 inches; and St. Augustine 2.5-3.0 inches.
Regardless of the turf species, mowing regularity should follow the one-third rule. This means never remove more than one-third of the total turf height at a single mowing. Therefore, depending on the rate of growth and the desired maximum turf height, this could require mowing several times a week for a hybrid bermudagrass lawn or perhaps as little as once every two weeks for a centipede lawn under low water and fertility management.
With irregular and improper mowing, excess leaf clippings collect on the turf canopy. This shades the turf, increases disease and insect incidences, and creates excess thatch. When the one-third rule is followed leaf clippings will fall into the canopy of the turf and decompose rather quickly.
Blade sharpness greatly affects the quality of cut and aesthetic appearance of the turf. A dull mower blade will tear rather than cut leaving leaf tips split, ragged and brown. It is best to avoid cutting the lawn when there is leaf wetness from rain or heavy dew for worker safety as well as to reduce turf disease pressure.
Large patch is most prevalent spring disease of Southern lawns
The fungus (Rhizoctonia solani) commonly known as large patch (also referred to as brown patch) is the most troublesome lawn disease for many Mississippi lawns. While this disease attacks most lawn turf species, it is most serious on St. Augustine and centipede lawns in the spring and fall.
Large patch is most severe when temperatures moderate at night in the upper 50 and 60-degree range with midday temperatures in the 70s and low 80s. Once summer temperatures get into the upper 80s and higher disease activity ceases until fall. Visual symptoms are brownish to gray irregular circular patches often with a narrow smoke-colored ring bordering the diseased area.
These water-soaked or scalded spots can spread rapidly from a few inches to several feet in size. The fungus generally attacks the base of leaf sheaths where they join to the stolons. When the disease is most active, infected leaves may slip easily from the stolons when pulled on and display a brown, wet, slimy decay at their base.
Large patch activity is enhanced by high nitrogen fertilization, moisture on the leaf surfaces, and excessive thatch. Therefore, to diminish the incidence of attack, be judicious with spring fertilization, particularly with fertilizers high in water soluble nitrogen.
Water early enough in the day to allow foliage to dry before nightfall. And maintain good mowing practices to manage thatch buildup.
When large patch becomes severe fungicide applications may be necessary.
For more information on large patch and other lawn diseases refer to Extension publication #1322 which can be obtained from the Newton County MSU Extension Service office.
