How to Kill & Reseed an Existing Lawn

If your lawn is beyond repair or simply not what you want it to be, you are left with no other option but to kill existing grass and start over. Also called total renovation, the process involves removing existing weeds and grass from the area and starting the planting and care process from scratch. Although time and labor intensive, completely removing poorly performing grass and improving the soil prior to reseeding gives the lawn a better chance to become healthy.

Measuring tape

Rubber gloves

Protective eyeglasses

Glyphosate herbicide

Pump sprayer

Rake

Tiller

Dethatcher (optional)

Soil pH testing kit

Lime or sulfur

High-phosphorus fertilizer

Organic compost

Shovel

Grass seed

Garden hose

Mulch

Measure the length and width of the lawn to determine how much weed killer you need. Ideally, 1 gallon of prepared weed killer (concentrate diluted in water) effectively kills grass over a 300-square-foot area.

Kill existing lawn grass when the planting time for the grass you want to grow is suitable. For instance, most warm-season grasses are planted in late spring and cool season grasses are planted in early fall. Wear rubber gloves and protective eyeglasses before pouring glyphosate in a pump sprayer and spraying it evenly over the unwanted grass. Direct the sprayer nozzle over each plant to ensure maximum contact and coverage. Start from one corner of the lawn and work your way to the other corner.

Inspect the grass after five days to a week for signs of browning. Repeat herbicide application over stubborn plants to kill the entire area and rake dead grass to collect it.

Till the soil to a depth of 6 to 8 inches. Alternatively, dethatch the soil to loosen it and remove accumulated debris, leaves and old grass. Test the soil pH value with a home soil testing kit. Ideally, grasses thrive in soil pH between 5.6 and 7.0. Increase existing pH with lime or decrease it with sulfur.

Mix equal amounts of high-phosphorus "starter" fertilizer and organic compost and spread an even, 3-inch-thick layer over the soil. Work it in with a shovel or tiller. Smooth out the surface of the soil with a rake to remove chunks of soil, debris, stones or rocks that remain.

Spread your selected grass seeds over the prepared soil with a mechanical seeder or by hand. Ideally, use 2 to 3 lbs. of grass seed per 500 square feet. Try to distribute the seeds evenly to prevent overcrowding. Make sure that the seed type thrives in your climate conditions and meets your requirements. Cool-season varieties include Kentucky bluegrass, ryegrass, tall fescue and fine fescue. Warm-season grasses for sunny areas include zoysia and St. Augustine. If blending grass types, mix two or more varieties of the same species.

Rake the seeds lightly to ensure they go 1/4-inch deep in the soil. Water the area until evenly moist and spread a 1/8- to 1/4-inch-thick layer of organic mulch such as straw to help maintain moisture.

Water the seeded area lightly to ensure the top 1 inch of soil is evenly moist, not soggy. Irrigate the area two to three times a day until the seeds sprout, which usually takes five days to two weeks. Afterwards, reduce watering to two or three times a week while the grass grows.

Because glyphosate is a broad-spectrum herbicide that kills any vegetation in its way, cover desirable trees or plants with a tarp or cloth while spraying to avoid affecting them. Also select a clear, non-windy day with no forecast of rain at least 24 hours before or after application.