The appearance of brown, dead patches in an otherwise green lawn is a common problem for homeowners. This “burnt” grass look often results from an over-application of fertilizer, concentrated salts in dog urine, or severe drought stress that desiccates the turf. When the damage kills the grass down to the roots, the only way to restore the lawn is through targeted repair and reseeding. Successfully reviving these areas requires a methodical approach, starting with addressing the underlying cause and preparing the soil before planting new grass.
Immediate Action: Flush Out Contaminants
The initial step for burns caused by chemicals, such as fertilizer or dog urine, is to dilute and flush the harmful salts from the soil profile. Both fertilizer and urine contain high concentrations of nitrogen salts that draw moisture out of the grass roots through osmosis, leading to dehydration and cell death. To counteract this chemical burn, the area must be saturated with water immediately upon discovery.
The goal is to move the excess salts away from the root zone, deeper into the soil where they become less concentrated. Soak the affected patch until the soil is fully saturated and cannot absorb more water. Repeat this deep watering daily for three to five days to ensure the contaminants are sufficiently diluted and flushed away. This prepares a non-toxic environment for new seed and can save grass that is only partially damaged.
Preparing the Damaged Area
Once the soil has been flushed, the next action is the physical removal of the dead plant material to create a clean seedbed. The brown, matted grass blades and thatch act as a barrier, preventing new seeds from reaching the soil. Use a stiff rake or a dethatching tool to scrape away the dead turf and debris down to the bare earth.
The soil surface must then be lightly loosened to ensure optimal seed-to-soil contact, which is necessary for germination. A garden trowel or hand rake can be used to scratch the top quarter-inch of the soil. This superficial aeration helps break up any crusting and allows the new grass roots to penetrate the soil more easily.
The Reseeding Process
The most effective repair for fully dead patches is to apply new seed directly to the prepared soil. Select a grass seed variety that matches your existing lawn to ensure the repaired area blends seamlessly with the surrounding turf. Avoid seeding during the hottest part of summer; instead, aim for the optimal planting windows of early spring or late summer to early fall.
Before scattering the seed, apply a thin layer of screened topsoil or compost over the loosened area, no more than a quarter-inch deep. This amendment provides a richer medium for the seedlings and helps hold moisture. Spread the grass seed at the rate recommended for patch repair, which is typically higher than for overseeding an entire lawn, ensuring uniform coverage. Spreading half the seed in one direction and the remaining half perpendicular helps achieve even distribution.
After the seed is spread, lightly rake the area again to ensure the seeds are nestled into the soil and covered by a thin layer of topsoil or compost. Finally, apply a light dressing of straw mulch or peat moss over the patch. This protective layer stabilizes the soil, prevents seeds from washing away during watering, and maintains consistent soil moisture for germination.
Nurturing the New Growth
Consistent moisture management is the most important factor for success after seeding. For the first two to three weeks, or until the seeds germinate, the top inch of the soil must be kept continuously moist, not saturated. This usually requires light, mist-like watering two to four times a day, particularly during dry or windy weather, to prevent the seeds from drying out.
Once the new seedlings reach approximately two inches in height, gradually reduce the frequency of watering while increasing the duration. This transition encourages the young grass to develop deeper, more robust root systems. Avoid applying nitrogen fertilizer until the new grass has been mowed at least twice, as a heavy nutrient load can burn the tender growth. Wait until the grass blades are three to four inches tall before the first mow, and never remove more than one-third of the blade height at any single cutting.