Repairing an existing lawn

Sick lawns can often be revived without starting over. Specific areas of dead or weedy lawn can be patched. You can also overseed for lawns that are thin or weed-infested, or simply to add a more appropriate grass to the lawn you have.

Patching a bare spot

This is idea for small, damaged areas, since you're replanting only the problem area.

1. Dig up and remove the damaged section, plus 6 inches of surrounding, healthy lawn, cutting 2 inches deep.
2. Smooth and level the soil. Add a small amount of soil amendment and starter fertilizer, firm the soil, water, and level again if needed.
3. Replant with seed, sod, or sprigs. For seed, cover lightly, press into place, and keep moist until germination. For sod, cut a section to fit, press it into place to firm roots against soil, and water frequently until rooted. For sprigs or plugs, plant them a few inches apart, cover lightly and press into place, and water until rooted.

Overseeding thin or winter-dormant lawns

This involves sowing seed over your entire lawn to correct thin areas or add grass that can better tolerate shade or resist disease. Overseeding is also used in the South and West to cover a dormant warm-season grass during the winter months.

1. Mow at the lowest possible setting and remove all clippings. If weeds are excessive, spray a post-emergence, nonselective, and systemic herbicide such as glyphosate. Spray when weeds are growing actively and then wait one week for the herbicide to kill the plants before mowing.
2. Dethatch. If your mower can't cut to the soil level, use a dethatcher. The blades of this rental machine cut down through thatch and stems and slightly into the soil. Rake up and remove all loosened debris.
3. Use an aerator (which you can also rent) to pull out 2- to 3-inch-long cores of soil, opening and cultivating the soil to prepare it for seeding.
4. Spread seed with a drop, broadcast, or handheld spreader. On bare areas, broadcast the seed two to three times the normal rate. Cover the seed to a depth of 1/16 to 1/8 inch by raking it in and lightly rolling or firming the soil.
5. Cover the area. Spread a thin, 1/4-inch layer of mulch over the seeds with a peat spreader to protect the seeds and keep the seedbed moist until germination.

See more about weeds, insects, and lawn diseases.