By Heather N. Kolich, ANR Agent, UGA Extension Forsyth County
Fall may still seem a long way off, but preparing warm-season lawns for fall and winter begins in late summer. These tips will help get your bermuda grass, centipede grass, or zoysia grass lawn ready for dormancy, prevent weed and disease problems, and help your lawn thrive next spring.
August
Make your last application of nitrogen. Nitrogen stimulates growth, but as the active growing season comes to an end in August for warm-season grasses, we want to allow growth to slow down in preparation for dormancy. Fertilizing in September can delay dormancy long enough for warm-season turfgrass to suffer from cold injury. Nitrogen in the fall also sets lawns up for Spring Dead Spot. It’s fine to make a final application of nitrogen in August, but as days get shorter and nights grow cooler, let warm-season turfgrasses go through the natural processes to enter dormancy.
Lower mower blade. The recommended mowing height for bermudagrass, centipedegrass, and zoysiagrass is 1-2 inches. If you raised mowing height by half and inch as recommended during the highest heat of summer, now is the time to lower the blade back to the normal mowing height.
Continue irrigation. For weeks with no rain, continue providing the lawn with 1 inch (total of rainfall plus irrigation) of water per week, preferably in two weekly applications.
September
Collect a soil sample for testing. Soil pH regulates nutrient availability to plants. Each species of turfgrass has its own optimal pH range. Fall is an excellent time to apply lime and other amendments to improve the soil that nourishes turfgrass.
Turfgrass species | Optimal pH range |
Bermudagrass | 5.5-6.5 |
Centipedegrass | 5.0-6.0 |
Zoysiagrass | 6.0-7.0 |
Lime can take several months to affect soil pH. A laboratory analysis is the only way to know how much of an amendment the soil needs to create the desired change in individual lawn environments.
For lawns, collect soil samples from a 4-inch depth in several randomly selected spots throughout the yard. Place all samples into a bucket, removing rocks, roots, and other organic matter, and mix them together to create an aggregate sample of at least two cups in volume. Spread the aggregate sample on some newspaper and allow it to dry completely. Once dry, scoop the soil into a zip-top plastic bag. Please call Forsyth County Extension at 770-887-2418 for soil sample payment and drop-off instructions.
Apply pre-emergence herbicide. If you’ve had lawn weeds in the past, chances are strong that you’ve got weed seeds in the soil. A pre-emergence herbicide prevents seed germination so that weeds don’t get a chance to grow. That’s why it’s important to apply pre-emergence herbicides in September, or before nighttime temperatures drop below 60 degrees Fahrenheit. That’s when soil temperatures become cool enough to allow winter weed seeds to germinate.
Pre-emergence herbicides contain various active ingredients and typically control several broadleaf annual weeds and some annual grass weeds. The products continue working in the soil for several weeks. Note that products containing atrazine should not be used on bermudagrass lawns.
While we don’t want to fertilize warm-season lawns after August, a pre-emergence herbicide that contains potassium will enhance winter hardiness in bermudagrass lawns. Look for pre-emergence herbicides that have 0-0-7 or something similar, with the first two numbers (for nitrogen and phosphorous) being zeros.

Seasonal tropical depressions that bring lots of rain and days of cloud cover can cause late season fungal problems. Starting a rotation of preventive fungicide applications can fend off leaf spot and other fungal diseases – without creating fungicide resistance problems – as the lawn goes into dormancy.
Fungicide rotation for lawns
Active ingredient | Diseases controlled |
Captan | Brown patch, Large patch, Dollar spot |
Myclobutanil | Brown patch, Large patch, Dollar spot, Spring dead spot, leaf spots, rust |
PCNB | Brown patch, Large patch, Dollar spot, Fading out, leaf spots, rust |
Thiophanate methyl | Brown patch, Large patch, Dollar spot, fusarium, Fairy ring, Gray leaf spot |
When using herbicides and other pesticides, follow the directions on the product label – including wearing personal protection equipment. Application rates are legal limits that define the minimum amount at which the product is effective and the maximum amount at which the product is safe to use for you, your plants, and the environment. For more information on lawn care and soil testing, please visit the Forsyth County Extension website.