Originally created 10/20/06

Overplant ryeseed when the weather turns cooler

Q:I was thinking about overseeding my lawn with ryegrass for the winter. Is it too late to do this? If it is not too late, could you provide some details on planting it? - Bill

A: It is not too late at all. Actually, we don't reach ideal planting time for ryegrass until mid-October. I usually say Oct. 1 at the earliest, but the prime time is about Oct. 15 through the first week of November. Any earlier than this and it is generally too hot. We have had so many days getting into the 80s and ryegrass doesn't like 80-degree days.

More and more, people seem interested in overseeding lawns. Many, particularly those who move here from the North and have been used to cool season grasses that stay green during the winter, are not fond of looking at a brown lawn.

Before you decide to overseed, there are several things to consider:

- You must be willing to cut the grass during the winter.

- You also must consider the amount of water needed to keep your lawn healthy. A lot of water is needed when the seed is first put out and until it gets well established. You probably will have a higher sewer rate for an entire year because your rate is based on winter water usage.

- Another factor is the permanent grass you have for your lawn. Bermuda is the best grass to overseed. It can be scalped close to the ground before overseeding, therefore making seed contact with the ground much easier. It is probably OK to overseed St. Augustine and zoysia, but you can't scalp them. Cutting them one notch lower is about all you can do before overseeding. I don't recommend overseeding centipede because the ryegrass is simply too much competition for it next spring when it comes time for it to green up. You should only overseed on a healthy permanent turf.

When overseeding with ryegrass, you have a choice between annual and perennial. Annual has quickly been replaced by perennial ryegrass because of the darker green color, improved quality, stress resistance, pest tolerance and manageability.

Overseeding rates in lawns range between 5 and 10 pounds per 1,000 square feet. 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.

The best way to overseed is to get good soil-to-seed contact. 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.

After dragging the seed into the soil, irrigate lightly two or three times per day until the seedlings are well established. Irrigate without causing puddling on the soil surface since too much water encourages disease. After the seeds germinate, gradually cut back on the frequency and increase the time of watering until you can establish a normal irrigation program.

Wait to fertilize until after the seedlings emerge. That's usually about three weeks after seeding. Earlier fertilizing might encourage warm-season turf competition. Generally, 1 pound of nitrogen per 1,000 square feet per month is adequate. This would equate to 6.25 pounds for a 16-4-8 or 10 pounds of a 10-10-10.

There is one downside to using perennial over annual ryegrass: Perennial ryegrass is not a true perennial this far south, but you will get a few patches of it that will come back. You will have to deal with those by using a herbicide to take them out or dig them up.