Richard Bogren, Young, John, Owings, Allen D. | 11/17/2009 8:52:41 PM
News Release Distributed 11/17/09
November and December begin the bleak time of the year for warm-season turfgrasses in Louisiana. Most turfgrasses should be dormant or at least close to this stage. Because the grasses are not actively growing, nitrogen fertilization should cease on home lawns unless they are overseeded with ryegrass.
Nitrogen fertilizer on dormant turfgrasses can lead to increased brown patch and winterkill. Also, nitrogen applied during this time has a greater potential for movement into groundwater.
Although many home lawns do not require regular mowing or fertilization at this time of year, now is an excellent time to have your soil tested.
For a soil test, take 1 pint of soil to your parish LSU AgCenter office. The sample should be a composite of soil plugs 4 inches deep from various places around the lawn. Specify the type of grass you are growing.
A soil test will give you a pH and provide valuable information on the current nutrient status in your soil. This aids determining a fertilization program for next year.
If you have chosen to overseed with ryegrass, apply 0.5-1 pound of nitrogen per 1,000 square feet every four to six weeks to maintain desired growth and color. Remember a warm-season lawn that has been overseeded will take longer to start growing and looking good next spring. Many times the perennial ryegrass used to overseed will remain through May and will compete with growth of the warm-season grass come spring.
Postpone until next spring establishing any permanent, warm-season turfgrass from seed. Sod, such as St. Augustine, can be laid during winter if necessary, but remember to keep it moist to prevent it from drying out and dying. Establishment is best left until mid-spring, well after spring green-up.
Brown patch diseases can come and go throughout the winter if the weather is mild. If you want to use a fungicide, check the labels to see if the one you are considering will control this particular disease. Damage from brown patch will slow spring green-up, and affected areas will remain unsightly until warmer spring weather conditions allow for turfgrass recovery.
Warm-season turfgrasses may show signs of greening up in south Louisiana in late February and by early to mid-March in north Louisiana. Do not push turfgrass growth with fertilizer then. Fertilizer applied too early will feed the winter weeds, and fertilizer applied too heavily will result in lush growth that is more susceptible to injury from late frosts or brown patch.
Let the grass green up gradually, and do not fertilize until after the first mowing. And remember, irrigate only as needed.