Overseeding Centipede Grass

Centipede grass lawns can be over seeded in the fall with a cool season grass to create a temporary, green lawn over the winter months. This is especially common in the lower South. An over seeded centipede grass lawn will not be as thick and green as an over seeded centipede lawn, but it is worth the try nonetheless. Here's how it works. The cool season grass germinates in the fall and begins to grow as your centipede grass is going dormant. As spring arrives, the centipede grass will begin to green as normal. During this "spring transition," the cool season grass and centipede grass will both be green and will be competing with one another. As the heat of summer arrives, though the cool season grass will die and leave the centipede grass to prosper for the rest of the summer.

Centipede grass can be over seeded with a variety of cool season grasses. The key is to choose one that will not linger too long into the summer, thus allowing your centipede grass to recover fully. Annual ryegrass is a good, generic choice for the South. It cannot tolerate hot weather and will die quicly as heat approaches. Perennial ryegrass can be used in the lower South although it will remain too long into the summer areas where fescue grows well. Creeping bentgrass is a good choice, but it is expensive. Do not over seed centipede grass with tall fescue or Kentucky bluegrass since they will last well into summer and compete with the centipede grass.

Steps in Over Seeding Centipede Grass

Do not apply pre emergence weed control in the three months prior to over seeding.
Over seed centipede grass lawns when the soil temperature drops to 70 degrees. This is usually around September 15 in the upper South and around October 15 in the lower South.
Prepare the lawn before seeding by mowing your centipede grass to about 1 inch and raking the lawn vigorously with a metal tined rake.
Sow 6-8 pounds of annual ryegrass per 1000 square feet and broadcast a complete lawn fertilizer that contains a slow release nitrogen, if you have not done so already. Apply at the rate of 1 pound of actual nitrogen per 1000 square feet.
Keep the soil surface moist for 7-10 days to ensure even germination. After that, water weekly if there has been no significant rainfall
Begin mowing as soon as the annual ryegrass reaches 2.5 inches. This is a good time to install a new mower blade, or sharpen an old one. A dull blade will rip seedlings from the lawn.
Continue to mow throughout the winter at 2 inches, whenever the grass reaches 3 inches.
Fertilize lightly every 4 to 6 weeks throughout the winter whenever the annual ryegrass is light green. Use a fertilizer like 10-10-10 that contains a soluble form of nitrogen, not a slow release form of nitrogen. Slow release forms of nitrogen are not effective during cold weather. Apply at the rate of .5 pounds of actual nitrogen per 1000 square feet. If using a 10-10-10, this equals 5 pounds per 1000 square feet. Stop fertilizing in February, however, to slow its growth so it will not compete with your centipede grass during the spring green up.
In March, mow your centipede grass to 1 inch. This will shock the annual ryegrass and give the centipede grass a change to emerge. Continue to mow frequently and consistently at 1.5-2 inches while your centipede grass is turning green. The remaining annual ryegrass will die once warm weather arrives.