Ag Line: Lawn green-up concerns
By Wade Parker County Extension Coordinator

Has anyone noticed yellow lawns in Jenkins County lately? I have had numerous calls pertaining to lawns that are having a hard time greening up. As everyone knows, lawns were looking very attractive before the Easter weekend freeze. I know of several lawns that looked great the Friday before the freeze. As Monday morning arrived, the lawns appeared as if it was February. This adverse weather has strained our grass to a great extent. To put it in simple terms, the grass has been "through the mill." Now, I would like to provide a few basic tips that will help our lawns get back on their feet.

It is very common for centipede grass to turn yellow as it is going, during the spring transition, from dormancy to active growth. As the root system develops, centipede grass color will fluctuate with soil and air temperatures. With the recent cooler temperatures, this would have been expected. Nitrogen, fertilization, or iron applications will not always appreciably accelerate a color change. Waiting on better environmental conditions is the best practice. This will likely solve itself toward the end of May.

Lawns that have been mismanaged for several years may experience turf loss. This is typically evident by gray stolons with no green buds. I refer to this condition as "centipede decline." If the grass is at least 50% viable, aerating or de-thatching will be a huge help. However, if the centipede is too far gone, re-establishment may be necessary. Either sodding large areas or seeding smaller spots is best done once the soil temperatures are consistently 65º F at the 4-inch depth. This commonly occurs around May 15.

Let's briefly discuss fertilization. The nitrogen requirement for centipede grass is 1.0 to 2.0 pounds of nitrogen per1000 square feet per year. One nitrogen application per growing season typically does not satisfy the growth requirements of centipede grass; therefore, several reduced rate applications are needed. Fertilizer should be applied as two or four applications consisting of 0.5 pound of nitrogen per 1000 square feet applications. Please keep in mind that this is not that much fertilizer. Overall, centipede is a low maintenance species and does not require much fertilizer. March and April are often too soon for the first nitrogen application. For most of Georgia, the first nitrogen application would not occur until May.

The recommended mowing height for centipede grass is 1.5 inches in the full sun and 2.0 inches in shaded areas. If the lawn is being mowed higher, gradually lowering the mowing height is recommended. Drop the mower one notch and mow at that height for several weeks, then drop the height again. Continue this "stair step" process until the proper height is reached. Some scalping and unattractive conditions may be expected.

Overwatering of centipede grass can also lead to the decline syndrome. Turfgrass needs 1.0 to 1.5 inches of water per week, depending on soil type, during the growing season. Sandy soils may need to be irrigated toward the upper end of the range. Irrigation should be used to supplement rainfall when weekly totals are below the recommended amounts.

I hope this information will bring our lawns out of intensive care and get them well! If you need any help with your lawn, please do not hesitate to call!

The University of Georgia Cooperative Extension offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability.