If you’re struggling with weeds in the lawn, your grass probably isn’t as densely planted as it should be. In other words, it’s “thin.” Thin lawns give openings for weeds, and once they gain a foothold, they can creep and seed their way to domination. “Overseeding” the lawn, which involves adding new seed to an existing lawn, helps eliminate those weed openings. Early Spring and early fall are the two best times to overseed a lawn. Here’s how:

Loosen soil with a hand cultivator
Small areas of soil can be loosened with a hand cultivator before scattering new grass seed.
George Weigel
Scatter seed and rake it in
Once seed has been scattered into the scratched-up ground, distribute it into the top quarter-inch with a rake.
George Weigel
Water overseeded areas daily
Water overseeded areas once or twice a day until the new seed has germinated.
George Weigel
  1. Prepare the area. First, remove as many weeds as possible. Pull larger ones, and spray creeping patches with an herbicide. Read the herbicide label to determine how long to wait before planting new grass seed. Also get rid of rocks, sticks or other debris. Then cut the lawn short – to about one-half to one inch.
  2. Loosen the soil. Grass seed won’t sprout well if you just toss it on top of compacted soil. Rough up the soil surface with a stiff-tined garden rake or claw-type cultivar. For large areas, consider renting a power tool, such as a dethatcher that roughs up the soil surface with fine tines, or a slit-seeder, which is a machine that cuts slices in the turf and deposits seed into them.
  3. Go with good seed. Different grass species perform better in some areas than others, and even within each species, some varieties perform better than others. Check out our article on How to Choose the Right Grass Seed, then browse our seed mixes to zero in specific varieties that have scored well in independent trials by the National Turfgrass Evaluation Program.
  4. Plant the seed. Scatter seed by hand in small areas or use a broadcast spreader over large ones. The goal is to distribute seed evenly and moderately – approximately 16 seeds per square inch. Then lightly rake so that the seed is distributed within the top quarter-inch of the loosened soil. Lightly tamp the soil to enhance seed-to-soil contact.
  5. Fertilize after overseeding with a fertilizer for new grass, such as GreenView Starter Fertilizer with GreenSmart. For lawns with crabgrass problems, consider  which contains a weed-preventing chemical that prevents crabgrass and other summer-sprouting grassy weeds without affecting grass-seed germination (exceptions are bermudagrass and some strains of bentgrass). Another option is to cover the ground after overseeding with a combination of mulch and fertilizer, such as GreenView Fairway Formula Seed Success Biodegradable Mulch with Fertilizer, or with a light layer of straw.
  6. Water. Keep the seeded ground consistently damp near the surface to sprout the seed and then to keep young, shallow roots from drying and dying. Figure on daily watering and possibly twice daily watering until new grass is two inches high. Then cut back to every other day or whenever the surface goes dry for the first season.