Lawn Removal Methods

Adapted from UC Master Gardener Program of Sacramento County 

Lawns are removed for several reasons. Many are choosing to reduce landscape water use and attract wildlife and pollinating insects by using native and other drought tolerant plants. The lawn removal method you choose will depend on lawn type and the amount of time, labor and expense you want to invest.

Lawn Type

Know your lawn type to select the method that will work best. There are three lawn types.

• Green-in-winter lawn (cool season grasses). These grasses grow in the cool season and include fescue and bluegrass. They are difficult to grow in California, but easier to kill.
• Brown-in-winter lawn (warm season grasses). These grasses grow in the warm season and are dormant and brown in the winter. Bermudagrass, St. Augustine and Zoysia grow well in California and are hard to kill due to their deep root systems. New plants can grow from small fragments of underground stems.
• Patchy grass with weeds. Patchy lawns with weeds such as crabgrass, Bermudagrass, nutsedge, bindweed, oxalis and dandelions. These weeds grow readily and are hard to kill.

Sheet Mulching

Sheet mulching kills the lawn by blocking out the sun needed for growth.  This method involves layering compost, weed barrier and mulch over the existing lawn. There are no scientific studies on the effectiveness of the order of the layers and our guidelines are based on success with the brown in winter and patchy lawn types.

Advantages of Sheet Mulching

• Does not require use of heavy equipment or chemicals.
• Works on all three lawn types with variation in depth of layers and time to completion.
• Can be started anytime of the year.

Site Preparation

• Mow the lawn as short as possible and leave the grass clippings on the lawn.
• Mark any sprinkler heads in the area to avoid damage.
• Water the lawn thoroughly to aid decomposition.
• Dig out the edges of the lawn 3 inches deep and 8-12 inches wide next to walkways, driveways and lawn edging to prevent water run-off from sheet mulched area. Excess soil can be piled on the lawn in mounds or used elsewhere in the garden.
• See table for details on the layers to place over the lawn.

Installation

• Spread a layer of compost over the lawn.
• Cover compost with layers of weed barrier. Separate pieces of weed barrier material and overlap by 6 inches to prevent light from getting through as layers shift over time.
• Wet weed barrier as you go to keep it in place while you complete the job.
• Spread mulch over the weed barrier.

What to do after installation-Time for lawn to die

• Water the mulched area to speed up decomposition of the lawn.
• Water less frequently than a growing lawn; water only until it is moist down to the soil.
• Time for lawn to die: cool season grasses take 1 to 3 months; warm season grasses and patchy lawns take at least 3 to 8 months.

Planting after the lawn has died

• Plant only after the lawn has died.
• The best time to plant is the fall. Spring planting can be done but more irrigation is required.
• Pull the mulch back from planting site, cut through the cardboard and plant into the native soil. Lay the cardboard back around the plant and respread the mulch. Do not let cardboard or mulch touch the stem or trunk.

Solarization

Solarization plastic traps the heat from the sun to kill the lawn and sterilize the top 3 to 4 inches of soil. This method can also kill plant diseases causing fungi and bacteria, weed seeds and seedlings in the top 3 to 4 inches. Beneficial soil fungi and bacteria are killed and earthworms retreat, but all quickly return after solarization. Although no chemicals or heavy equipment is needed, there are multiple disadvantages with this method.

Disadvantages

• Works only for cool season grasses. Less effective for warm season and patchy lawns as the grasses and weeds can regrow from roots, seeds and stems that survive below the top 3 to 4 inches of solarized soil.
• Works best in hot summer temperatures and requires 6 to 8 hours of sun daily; begin process in summer to be completed by fall.
• Restrict foot traffic from people and pets during this process to prevent tears in plastic.
• Ultraviolet (UV) resistant plastic works best but can be difficult to find.

Site Preparation and Installation

• Mow lawn as short as possible and leave clippings on the lawn or remove clippings to create a flat even surface. Remove all twigs, plants with thorns or anything that could puncture plastic.
• Dig out the edges of the lawn 6 inches deep and few inches wide. This trench will be filled with soil, sand or rocks to seal plastic over the lawn.
• Use clear UV resistant plastic: it is most effective as it lets the sun’s heat to pass through to the lawn and won’t degrade in the sun. Regular plastic often degrades and needs to be replaced before project completed. Black plastic is not as effective as it absorbs some heat. Thin 1 mil is effective but tears easily; 1.5 to 2 mil works well.
• Water the lawn thoroughly to a depth of 12 inches. Immediately cover with plastic, securing edges in trenches with soil, sand or rocks. The plastic should lay as close to the lawn as possible. If you have to overlap plastic, allow 6 inches to overlap at seams.
• Monitor and repair any breaks in the plastic.
• Cool season lawns will die in about one month. Warm season grasses and patchy lawns take one to two months to die. Remove plastic in the fall to prep for new plantings. Use plants that are smaller than 1-gallon size to avoid the need for deeper planting holes which could raise viable weed seeds from below solarized layer.

Sod Removal

This method removes lawn, roots and soil.

Pros and Cons:

• Works only for cool season lawns. It is the fastest method of lawn removal for these lawns.
• It does not work for warm season or patchy lawns because cutting at the soil line does not kill roots below the removed sod, so they regrow. This method is not recommended for lawns with a lot of surface tree roots which can be damaged in the process.
• Labor intensive and involves equipment. A large lawn may require the help of a professional.

Herbicide

For persistent grasses like Bermudagrass, post-emergent non-selective products are available. Non-selective herbicides kill the top growth and roots of the plant. These work best on actively growing plants at temperatures of at least 60 degrees with optimal temperature of 75 to 85 degrees. Non-selective herbicides will kill any plant it comes in contact with but have a relatively short life in the soil and water. Read and follow all label instructions.

• Works for cool season lawns that are actively growing and not drought stressed.
• Warm season and patchy lawns should only be treated during active growth and warm temperatures. Because these lawns can regrow from roots and seeds, three applications of herbicides may be needed. Read and follow all label instructions for repeat applications.
• Start in spring through early fall. Water the lawn well for two weeks and allow it to grow to a height of 6 inches as this will provide more leaf surface area to absorb the herbicide.
• Avoid spraying on windy days or if rain predicted within 24 hours. Wear protective clothing and follow all directions on the herbicide label.
• Don’t disturb the sprayed area for 7 days and allow two weeks for the lawn to die. Mow and water the area again and wait at least two more weeks for any new growth to appear.
• If no new growth appears, you can plant. If new growth appears, wait until sprouts are actively growing the reapply herbicide. It may take from one to three months for treatments and monitoring of new growth to be completed depending on the type of lawn.

References

Lawn Removal Methods. UCCE Master Gardeners of Sacramento County. UC ANR. Beyond Lawn - Sacramento MGs (ucanr.edu)

How to Remove a Lawn. Yolo county Master Gardeners. UC ANR. 187332.pdf (ucanr.edu)