Horticulture Hotline 03/14/22
Bill Lamson-Scribner
A mix of several conversations I have had in Possum’s this year. Between moles and other unknown causes, my lawn took a beating this season. I have a lot of patchy, bare areas. I was thinking of aerating and planting centipede seeds, rather than sodding. Is this advisable? What is the best time of year to plant the seed?
The size of your patchy, bare areas will determine your course of action. One thing that you must consider if you are going to use seed is that you will not be able to use preemergent herbicides in their regular cycle. If you do not use preemergent herbicides, weeds will move into these patchy areas. If the areas are small enough, just add a little extra fertilizer, SeaHume and Cotton Burr Compost and grow the patchy areas in from the sides. Centipede is a grass that grows on runners, so it will fill in quickly from the sides.
Aerating is a good cultural practice that should be done in April once the grass is actively growing. If you were to seed the centipede you would wait a month after aerating. Centipede seeds are small, so you wouldn’t want them to fall into the aeration holes or they would be planted too deep (they have fallen and can’t get up).
Generally, you do not seed centipede until late April or early May depending on the soil temperatures and when the night time temperatures are staying above 65 degrees consistently. Centipede seed takes a while to germinate (10-28 days), so I always like to “push” the grass with a little extra fertilizer, SeaHume and Cotton Burr Compost. Waiting for centipede seed to germinate takes some patience. Without preemergents on your lawn, weed seeds will be germinating while you are trying to get the centipede to come up and will compete with your new centipede seedlings. You will want to manage these weeds as they appear.
When you were a kid did you germinated a lima bean or some other seed between layers of moist paper towels? While you are germinating centipede, you want to create the same environment without burying the seed too deep. A light layer of Nature’s Blend (contains a natural growth hormone), Hydro Mulch (the blue / green product you see sprayed out on roads or pond banks) or even shredded newspaper) will help keep the seed moist. The seed needs to stay moist for 10-28 days, so these products will help keep the seed moist by buffering the wind and sun.
When I hear “moles and other unknown causes” that you were having problems with, try to determine what the unknown causes are so you don’t fall into this same situation next year as well. Is there shade, irrigation and/or drainage issues? A soil test and program would be most advisable. This will help determine any needs of your soil so your grass can grow at its best. Centipede grass is very particular about the soil pH range it grows in. This is a great time to take a soil test and get on a program so all systems will be “grow” come springtime.
Centipede grass has the reputation of being a low fertility grass. In fact, Clemson was doing research at their Pee Dee station and was trying to kill the grass with excessive fertilizer. They went into the research thinking that the grass would die over the winter from use of high rates of nitrogen; however, after several years, this never happened. If your grass is full and thick, you would not want to over-fertilize it with nitrogen. Since your grass is thin and patchy, a little extra fertilizer won’t hurt it any.
Centipede seeds are very small. Unlike Fescue or Rye grasses, you don’t just aerate it and then seed. If your areas are big enough that you decide that they are too big to run the grass in from the sides, you could buy some squares of centipede and plug them in to fill the gaps. This way you are starting out with something green and you are able to watch it grow. Seeding can be very successful and inexpensive. One pound of centipede seed is recommended to cover 2,000 square feet.
Zoysia grass seed is another warm season grass seed that would be very similar to establish as centipede. There are a lot of varieties of Zoysia grass, so there might not be a seed that matches your type.
If you decide to seed with Zoysia, wait until night time temperatures are above 65 degrees consistently. Be patient because it takes about 21 – 28 days to germinate. Use 2 to 3 pounds of seed per thousand square feet.
Good luck!
