Overseeding lawn can keep it green in winter

I can't decide what to do about my front lawn. I am considering overseeding my hybrid bermudagrass with perennial ryegrass so I will have a beautiful green lawn all winter. I was considering this because my lawn has never looked better, and I want to keep it that way all winter.

I will need to decide soon, as it is time to put out pre-emergence herbicide to prevent winter weeds. You can't do that if you put out ryegrass, because the herbicides cannot distinguish between weed seed and ryegrass seed.

In our area, the best time to overseed is Oct. 10 through the first week of November. That's two to four weeks before the average first fall frost.

Ryegrass does not like 80-degree and higher days, so there is always the risk of it getting too hot until the middle of the month. After the first week of November it may start getting too cold, which can slow or retard germination.

There are many factors to consider in deciding whether to overseed a lawn.

My primary concern is the watering it entails. Once the seed is out, it will need daily watering until it comes up. Then, it will need watering through the winter to keep it looking its best. Watering during December, February, and March will cause the sewer bill for an entire year to be higher, because those are the months that Richmond and Columbia counties use to set rates.

Overseeding will also mean I'll have to cut grass during late fall and winter.

Overseeding should be done only on a healthy, permanent turf. It would cause more problems for a weak turf next spring at green-up.

The best and easiest lawn to overseed is Bermuda, which can be scalped before application to give the seed better contact with the ground.

You can overseed St. Augustine and zoysia, but about all you can do is lower the mower's blade a notch for the cut before overseeding. I don't recommend overseeding centipede because the ryegrass will be too much competition for it next spring.

Perennial ryegrass is a darker green color than annual. It also has improved quality, better stress and pest tolerance, and manageability. Buy seed treated with fungicides.

You'll need 5 to 10 pounds of seed per 1,000 square feet. Use a higher rate if you want a thicker stand. Use high-quality, certified (blue tag) seed that's free of annual bluegrass (Poa annua) to maintain weed-free turf.

The 10-pound rate provides a fast stand for fall use. The 5-pound rate provides a thinner stand that doesn't provide much coverage until spring.

The right seeding rate depends on how you want it to look and how much traffic the turf will bear. Higher traffic areas need higher seeding rates. However, higher seeding rates may also mean a more difficult spring transition.

Seedbed preparation begins with the scalping or cutting a little closer, coupled with some light vertical mowing, and sweeping or vacuuming up the dead or loose plant debris. Generally, the more the turf is opened up, the better the establishment rate. Seeds that germinate in thatch or above the soil are more likely to dry out and die.

Irrigate lightly two or three times per day after seeding until the seedlings are established. Avoid puddling: Too much water encourages disease.

Gradually cut back on the frequency and increase the time of watering until you can establish a normal irrigation program.

Fertilize about three weeks after seeding. Earlier fertilizing may encourage warm season turf competition.

One pound of nitrogen per 1,000 square feet per month is adequate. That equals 6.25 pounds for a 16-4-8 or 10 pounds of a 10-10-10.

Sid Mullis is the director of The University of Georgia Extension Service office for Richmond County. Call him at (706) 821-2349 or send e-mail to smullis@uga.edu.