Reseeding your existing lawn
The best time of year to reseed your existing lawn is in the fall. In most areas of the United States, the ideal is to sow the grass seed in late August or September. It will germinate while temperatures are relatively warm, then grow and mature as temperatures begin to cool. If you didn't do it last fall, don't despair. You can do it in late winter or early spring before temperatures warm up.
First, rake the lawn with a heavy-duty broom rake. It comes with either wire or flat steel teeth. This rake also has looped spring braces between the handle bar and spacer bar.
Next, remove the thatch from your lawn. Thatch is a build-up of dried clippings and other dead plant material that forms a layer above the soil surface. Removing it allows for new grass seed to come into contact with soil, increases air circulation and makes it much easier for water to penetrate.
To de-thatch your lawn, you will need a heavy-duty garden rake with stiff steel teeth. De-thatching attachments are also available for most riding mowers and lawn tractors, either for purchase or rent.
Once the layer of thatch has been removed, the thin and bare spots in your lawn will be easier to see. Areas marked for reseeding should be free from weeds. It's wise to apply herbicide twice, spacing applications 3 weeks apart.
Use a cultivator to loosen the soil to a depth of 1 inch. Do not rototill your lawn, as doing so will cause weed seeds to germinate. Pulverize the lumps of soil.
Apply a starter type lawn fertilizer first, and rake it into the soil. Never mix grass seed and fertilizer in the same spreader.
Determine the type of lawn seed based on available light and moisture, and amount of traffic it will receive. Make sure to choose a top quality seed. Read the seed tag to determine the ratio of grass to weeds, and what percentage is inert ingredients. Don't ruin all your hard work with a low-quality "bargain" seed.
Freeze your grass seed overnight for faster germination. It's OK to keep it frozen until you're ready to put it down on the lawn.
It's a good idea to rent a verti-slicer or seed slitter, especially if you have a large area to cover. Most come with a seeder attached. Set the machine to cut ½ inch slits, and the seeder to drop 4 or 5 seeds per inch. Make east to west and north to south passes with the machine in a checkerboard pattern.
You can also use a broadcast spreader or shoulder seeder to manually spread the grass seed, but be sure not to spread it too thickly, as only about 6 seeds per square inch will survive.
Water the newly seeded areas immediately with a light mist. Lightly cover the areas with straw if you wish.
If time is short, cover the seeded areas with sheets of clear polyethylene plastic held down with rocks or land pins. Constant watering is eliminated, because the plastic keeps it in the soil.
Remove the plastic sheeting at the first sign of seedlings. It is used to speed germination only and will kill all newly emerging grass seedlings if left on. Once the covers are removed, you'll have to water with a light mist 2 to 3 times per day until your seedlings are 1 inch high.
Afterward, continue to water once per week so the new grass receives a total of 1 inch of water and rain combined per week.
When your grass reaches 2 ¼ inches high, it is ready for its first mowing. Mow your lawn to a height of 2 inches. Mow the grass often, because the more cuttings it receives, the faster it will mature. Should you need to apply granular weed killer, wait until the new grass has been cut at least 3 times.
Are you planning to reseed your lawn this fall? Tell us about your experience in the comments area below. What worked for you and what didn't?