Renovating, or overseeding, involves revitalizing an old lawn without removing all the existing grass. Many old, thin, weed-infested home lawns are completely restored using this approach. Renovation is most successful when more than half of the existing lawn is still producing desirable turfgrass.
1. Remove thatch. If thatch (dead, dry vegetation) has built up more than an inch, remove the thatch with a rake. Thoroughness is important; seeding into thatch results in poor seed germination.
2. Remove clippings. Using a mower with a grass-catcher attachment, collect and remove the discarded thatch. For small areas a spring rake works well.
3. Apply compost. Spread about ¼ inch of compost over the areas to be seeded.
4. Reseed. Uniformly scatter seeds over the soil surface using a drop or rotary spreader. Handsprinkling seeds also works well on small, irregular patches that need overseeding.
5. Rake. Lightly drag or rake the seed into the upper ¼ inch of soil and compost.
6. Roll. Roll the area to ensure firm contact between seed and soil.
7. Mulch (optional). Sprinkle weed-free straw (salt marsh hay) lightly over the seeded area.
8. Water. As with new lawns, keep the overseeded area moist at all times during the germination and early seeding stages.
9. Mow. Continue mowing the lawn at approximately 2-2½ inches.