No matter how much TLC you give your lawn, chances are you’ll occasionally need to patch a sparse area. It’s not difficult, but timing is everything. “The earlier you get warm season grasses started, the better,” says Clint Waltz, PhD, turfgrass specialist at the University of Georgia. “Plant after the last expected frost date in your area when the soil temperatures are 65 degrees and rising.”
Generally, that means the ideal window to repair bare areas in warm season grasses is mid to late spring, though you can plant grass seed until about early August. “If you plant later than that, however, the grass will germinate but it won’t get far. When nighttime temperatures begin to drop into the cooler range, the young grass will stall and die,” says Waltz.
Warm season grasses found in most Southern lawns include Bermuda, Zoysia, Centipede, or St. Augustine. When you repair a bare spot, match it to the rest of your lawn so it won’t end up looking like a patchwork quilt with various colors and textures, says Waltz. Talk to your local university coop extension service (find yours here) to ID your grass if you’re not sure what species you have.
First, prepare the surface by removing all the wispy-looking grass, rocks, and sticks. Till up the area about 3 to 4 inches deep with a tiller or rotary hand cultivator. Then pat it down or use a lawn roller to firm it up enough so that you can walk across it and barely leave footprints, says Waltz.
Sprinkle seeds over the bare soil; there’s no need to rake them in. “The most important thing is to ensure good seed to soil contact for germination,” says Waltz. The bag usually suggests seeding rates, but aim for about 80 to 90 percent surface coverage in the first growing season. That means you’ll spread about one pound of seed per 1000 square feet.
If the seed is coated with lime or materials such as a fungicide or wetting agent (which add to its weight), you may wish put down double the suggested rate for better coverage, says Waltz. Then barely cover the surface area with straw to keep seeds moist and prevent erosion.
Next, water the area, keeping it consistently moist but not sopping wet. Once germination occurs, the area must remain moist; the new grass has no reserve and will die if it dries out, says Waltz. And, finally, be patient! Warm season grasses, such as centipede, can take up to three weeks to germinate and three more to take off.
Sod is a great repair option for all types of lawns. In fact, St. Augustine grass is available only as sod (not seed). Sod typically is sold by the slab, a piece roughly a foot wide by 18 inches long. Most sod is shipped within 150 miles of the farm so that it’s fresh when you buy it. But it is perishable, so make sure it was delivered to your retailer within the last day or two, and get it down as soon as possible at home.
Prepare the planting area in the same manner as for seed, tilling it up a few inches deep. Add or remove topsoil, if necessary, to ensure the sod is flush with the rest of the lawn. Cut the sod to fit with a garden knife, then use a lawn roller on top to ensure the sod has even contact with the soil.
Water the sod, keeping it moist. Check to see if water has penetrated to the roots by lifting up a corner to check the bare soil, then adjust watering accordingly, says Waltz. You’ll know it’s started to root if you give the corner of the sod a gentle tug and it doesn’t lift up easily.
Yes, but if you have an older Zoysia grass lawn (it’s more than 30 years old), you will need to take plugs, or small sections, from another area of your lawn to repair bare spots. That’s because previous varieties of Zoysia, such as Emerald and Meyer, are no longer sold. If you attempt to patch an older lawn with either of the two Zoysia seeds now commercially available (Zenith and Compadre), your lawn will end up looking mangey, says Waltz.
Mow for the first time when grass reaches its mature height. For example, that’s around 1 ½ to 2 inches for Bermuda or Zoysia. Also, wait to fertilize until your grass has gone through a couple of mowings because otherwise, nutrients just leach out of the soil without a root system to use them, says Waltz.
One final note: If you find yourself repairing the same areas year after year, such as where the dog runs along the fence or you step off the deck onto the grass, maybe it’s time to rethink things. In high-traffic areas where the soil is compacted repeatedly, you may be better off replacing grass with a low-maintenance solution such as pavers or ground covers, says Waltz.