What is overseeding?

Overseeding is the practice of adding seed to an existing lawn. It is commonly done to fill in bare spots, to introduce new grass varieties with different strengths or tolerances, and to build grass density or alter a lawn’s color. To overseed a lawn, mow it lower than usual, collect the clippings and rake. This prepares the soil so seed can make contact needed for rooting. Overseed cool-season grasses in spring or fall. For warm-season grass types, overseed in late spring through mid-summer.

Digging deeper: Seasonal Overseeding Explained

Confession: I don’t overseed my lawn in the winter, but I absolutely love to see a green, lush yard in the middle of winter. It gives me the warm fuzzy feeling that warm season grasses can still be green in the dormant season.

Nevertheless, when I dropped my kids off at school the other day, a super-green football field caught my eye. It should be getting sort of a mix of tan and green this time of year, but it was bright green, and it was just waiting on a school game to kick off. I realize that some people overseed, but most are intimidated by the process. I get asked all the time how to do it, so I went right to the expert to get instructions.

Graham Simmons, Woerner Farms’ Production Manager was the perfect person to explain how to overseed correctly. He gave me several easy tips critical to this seasonal practice. Here are your tips for the warm season grasses. Keep in mind, this is for two different grasses – one that is going dormant, and one that is about to kick off and grow.

• Overseeding is recommended for bermuda lawns, but it can be used on zoysia and centipede.
• Watch your pre-emergent schedule. Don’t do a pre-emergent for winter weeds and then expect to overseed right after. The pre-emergent will actually harm seed germination.
• Prep the area by mowing lower than usual. To help expose more seed opportunities, mow to 1/2 – 3/4 inch height.
• Choose the right seed. Choose a perennial rye, and one that is more of a dwarf blend that will compliment what your grass would normally look like. Some blends can grow really tall and rogue. These are typically engineered more for pasture environment than for a homeowner. According to Dr. Wayne Wells, an Extension Professor and Turfgrass Specialist at Mississippi State, “Seeding rate for home lawns with perennial ryegrass should be 8-10 pounds per thousand square feet.”
• Spread evenly and according to package instructions. Be careful that you don’t create a spotted, patterned, or uneven overseeded lawn. You would be surprised at how easy it is to distribute seed incorrectly if you don’t follow the instructions.
• Get the right fertilizer. If you are going to take a fall soil sample, choose the crop code for your warm season grass and follow the instructions. It is critical that your nutrient levels are not only correct to put your dormant grass to sleep but also to help the new seed thrive.
• Adjust your watering regimen. Go back to a more frequent watering schedule for at least the first 2 weeks to jump start germination.
• Mow back at normal height. Once the overseed germinates and begins to grow, raise the mow height back to the normal mowing height.
• For all of you who live in cooler climates and have bare spots or problem areas in the cool season grasses, now is a great time to think about overseeding those areas. Remember though that your problems could be a result of poor soil quality or bad fertility. Make sure you do a soil sample to ensure you are not chasing a problem with wasted efforts and money.
• Once you determine that your soil is healthy, make sure to rake and prepare the ground for seed germination. Again, choose the right seed that compliments the grass you either want or have in your lawn. Follow the instructions and make sure you water frequently for at least the first two weeks and then pull back the water schedule once the grass is taking a nice, strong stand. Use the fertilizer recommended by your soil sample. And finally, enjoy a fuller lawn.