Throughout the summer, our homes have been beautified by lush lawns. The hot weather will soon give way to the cooler temperatures of autumn, and several steps need to be taken to ensure our lawns stay healthy and attractive.
Lawns consisting of warm-season grasses, such as bermuda, zoysia, centipede and St. Augustine, will start turning brown and going dormant in October and November as the weather becomes colder and the days shorter. Avoid applications of fertilizer containing high amounts of nitrogen since doing so could delay dormancy and make the grass more susceptible to cold damage.
Also, the fertilizer can increase the risk of the lawn developing certain fungal diseases. Before applying fertilizer, have your soil tested through UGA Extension Gwinnett. Fertilizer applications are not necessary during the winter since the grass is not growing and will be unable to utilize the nutrients. Additionally, the material could be washed off-site by rainfall and potentially contaminate water bodies.
Continue to cut warm-season grasses as they slow in growth. As the grasses become dormant later in the fall, lower the blade one-half of an inch. This action will help give the grass a cleaner appearance for the winter. Rainfall and supplemental watering should total one inch per week until the grass begins to turn brown. During the winter, rainfall will supply the necessary amounts of water the grass needs.
Sometimes warm-season grass is over-seeded with ryegrass, which grows during the colder weather, keeping it green during the winter. You may observe this practice on athletic fields and golf courses. The major drawback is that the ryegrass can interfere with the greening-up process the following spring by competing for nutrients, water, and light.
Turfgrass managers will scalp the grass close to the ground, which will allow for air and light to reach the grass blades as they are starting to grow while stunting the growth of the ryegrass.
Cool-season grasses thrive in cooler weather, and the heat of the summer stresses them. The main variety planted as a lawn grass in our area is tall fescue. Kentucky bluegrass can be used in the mountain regions and points north, but it will not survive our summers.
Since the fescue lawns have thinned out in areas due to the summer, the cooler months of September to mid-October are the best times of the year to over-seed the lawn. The seed application rate is five to seven pounds per 1,000 square feet.
Apply fertilizer according to soil tests. Two to three weeks before seeding apply RoundUp according to label directions to control unwanted weeds in the lawn in addition to any bermudagrass that has crept into it. In bare spots, use a rake for scratching the soil to allow for good seed to soil contact. Cut the lawn one-half of an inch lower to reduce the need for mowing.
Apply water as required to keep the soil evenly moist while the seed is germinating. Wait two to three weeks after over-seeding to mow to ensure the grass is strong enough to handle it.
The month of September is the time to apply a pre-emergent herbicide to control winter weeds such as annual bluegrass, henbit, and chickweed. It kills the weeds as they are germinating as opposed to a post-emergent herbicide, which controls existing weeds.
The chemicals will not prevent all weeds but can reduce their population. If you are over seeding your fescue lawn, then do not apply pre-emergent herbicides since the chemicals will inhibit germination of the seed. As with all pesticides, follow all label directions when using.
Now is the time to take steps to ensure you have an attractive, healthy lawn during the cold weather months. If you would like to learn more, UGA Extension Gwinnett is offering a class on fall lawn care that will be held Sept. 16 from noon to1 p.m. in the second floor conference room of the Gwinnett County Government Annex Building, 750 South Perry St. Lawrenceville, GA 30046. There is no charge, but please register by contacting the UGA Extension Gwinnett office.