The first step to creating any new garden bed in your lawn is to remove the existing sod. There are several methods you can use to remove turfgrass, each with its own advantages and limitations. The method you choose depends on the time required, the amount of work involved, and your personal preferences.
Use the guide below to determine which sod removal method is best for your situation.
Smothering | Heavy Mulching | Digging | Tilling | Herbicides | More Information
Smothering
By layering materials such as newspaper, cardboard, or plastic, you can exclude light, halting photosynthesis and causing the plants to eventually die. Smothering allows all of the organic matter to stay in place. This is one of the least labor-intensive methods for removing sod, but it is also one of the most time-consuming, often requiring the paper or plastic to be in place for six weeks or longer. Soil health can also be negatively impacted should these smothering layers remain in place after the underlying vegetation is killed. When done appropriately, this approach is one of the most eco-friendly options.
Newspaper & Cardboard
Lay 6 to 8 sheets of newspaper or 1 to 2 layers of cardboard over the area where your new garden bed will be. Thicker is not better, as newspaper and cardboard can inhibit water and air movement into the soil, especially when layered too thick. Most newspapers use organic inks, so you don't need to worry about lead contamination. Avoid using waxed cardboard and glossy paper, such as magazines. Remove packing tape and staples from boxes. Cover the newspaper or cardboard with an organic mulch such as compost, shredded bark, or leaf mold. This improves the appearance and prevents the paper from blowing away.
It will take several months to completely kill the plants beneath the paper, so starting the process in the fall for spring planting is a good timeline. Ideally, the layer of paper or cardboard is removed or broken up once the underlying vegetation is completely killed so as not to obstruct water and air movement into the soil for your new garden plants. You can plant right away through the mulch-covered paper if there isn't time to wait for the grass underneath to die. Although this thick smothering layer can make it difficult to water the newly planted plants, the new plants will be in the way when it comes time to remove or break up the sheets of paper or cardboard.
Plastic
Stretch a single layer of light-excluding plastic over the area. The layer of plastic not only stops photosynthesis by blocking light but also dries out the plants by preventing moisture from reaching them. Plastic has the added benefit of solarization, which heats the ground and kills the grass faster. However, the extra heat can sometimes kill beneficial organisms in the soil. You will not be able to plant the area right away and will need to wait several weeks (often 6 to 8) for the grass and its roots to die before planting. Hold the plastic in place with bricks or landscape staples. The plastic can also be covered with mulch to improve its appearance, but it will need to be pulled up before planting because it is not organic.
Heavy Mulching
This method utilizes a temporary layer of mulch to smother the grass. Once killed, the excess mulch is removed from the garden area and then planted. The heavy mulching method has many of the same advantages as smothering (as it's essentially the same thing, just without a sheet material), such as allowing all organic matter to remain in place and avoiding soil disturbance. Additionally, the lack of an impermeable (plastic) or nearly impermeable (newspaper and cardboard) layer eliminates many of the disadvantages associated with more typical smothering methods that use sheet materials.
Start by mowing grass and weeds as low as possible. Layer at least 8 inches of wood chip mulch (shredded or chipped) over the area. A depth of 12 to 18 inches is even better. The woodchip mulch will settle over one to two weeks, so be sure to apply enough mulch so the final depth after settling is at least 6 to 8 inches. Keep the mulch in place for several weeks, allowing it to smother and decompose the underlying vegetation.
Pull back the mulch in a few places after 2 to 4 weeks and check on the grass. When the turf layer is dead and decomposed enough to dig through it easily, you can plant. Be sure to pull all the mulch back and plant in soil (not in the thick layer of mulch). Replace enough mulch to provide the typical 2 to 4-inch depth needed for a garden bed. The excess mulch should be removed and can be used elsewhere in the garden.
Digging
Using a spade, garden fork, or sod cutter, the existing turfgrass can be physically removed, leaving a weed-free garden bed for planting. Digging allows you to create a grass-free area quickly but requires a lot of physical labor. As with smothering, this method of grass removal is eco-friendly since it utilizes no chemicals. However, digging removes a lot of organic matter and topsoil. While some soil can be shaken off the sod pieces, in most cases, organic matter and soil will need to be added back to the new garden bed after the sod is removed.
Use a sharp spade to dig down, then slide it horizontally just under the shallow grass root system (about 1 inch deep). Remove the sod in sections, or roll it up as you slice beneath it. The sod pieces can be reused in other areas of the landscape. Sod pieces or rolls can be quite heavy, so keep them to a manageable size. If the sod is thick, a garden fork can be used to slice beneath it, leaving behind more topsoil while still pulling up pieces of sod that can be easily removed. For large jobs, consider renting a sod cutter. This can significantly reduce the effort and time required to cut out the sod.
Whether you use a spade, fork, or sod-cutter, expect to have some tired muscles at the end of the day! Remove the sod a couple of days after a soaking rain, or irrigate two or three days ahead of digging to make cutting through the soil easier. Don't work in overly wet soils - it makes the sod heavy and can lead to compaction of the soil in your new garden bed. Cover the new grass-free garden bed with mulch as soon as possible to prevent weeds from sprouting.
Tilling
Much like digging, tilling allows you to quickly create a turfgrass-free area for planting. Unlike digging, it allows you to retain much of the organic matter. Tilling also allows you to easily incorporate additional organic matter before planting. Most lawn areas will require a large rear-tine rototiller to break up the sod. Tilling 3 or 4 days after irrigating or after a good soaking rain helps reduce the physical effort required to work the tiller through the area. Just don't till soil that is too wet. If the soil sticks to the tiller's tines or forms a ball that holds its shape easily, wait a day or two for the soil to dry out further.
After the soil has been turned, use a garden rake to level it and pull out large clumps of leaves and roots. The new garden bed is ready for planting right away, but would benefit from allowing the area to sit for two to four weeks to let new weeds sprout. Once the new weeds have begun to grow, lightly hoe the plants or spray them with a non-selective herbicide to kill them. Then, cover the bed with an organic mulch. This method of weed control is called the stale seedbed technique. The primary disadvantages of tilling are that it can degrade soil structure, bring up weed seeds that readily germinate, and chop up plants and roots that can resprout easily. Utilizing a stale seedbed weed control technique allows you to reduce the number of weeds that could become established in the new garden bed.
Herbicides
Treating the area with a non-selective herbicide is a quick, easy way to kill grass that requires minimal physical exertion. The primary disadvantages of using herbicides are the much higher potential to damage nearby non-target plants, unintentionally contaminate the environment, and injure beneficial organisms or people. Read the product label carefully and be sure it is labeled for the control of grass and any other weeds or plants in the area. Take special note of how long the product remains active in the soil. You will not be able to replant the garden area until after the re-entry interval listed on the label. For some products, this may be as little as three days; for others, it may be three months or longer!
Always apply herbicides when winds are calm and temperatures are cool to prevent drift and damage to desirable plants. Check the forecast to ensure there is no rain in the forecast within the application period denoted on the product label. Wear long sleeves, pants, gloves, eye protection, and any other protective equipment outlined on the product label. Most herbicides are only effective when applied to green leaf tissue, so be sure to apply while the grass is actively growing. When applied appropriately, most herbicides will show damage to the grass 2 to 7 days after application. Healthy turfgrass will likely require more than one application to fully kill leaves and roots. Once the grass is dead and the re-entry interval listed on the label has passed, the area is safe to plant. There is no need to dig out the dead vegetation. Plant through the dead sod and cover the area with mulch. Keeping the dead plants and root systems in place provides organic matter and can help reduce the risk of erosion.