How To Garden Where There Is Grass

If you are thinking about turning an area of lawn into a garden bed, your first step will be to get rid of the grass. You can take different routes to accomplish this: Those that yield quick results can require considerable effort, while less labor-intensive methods may take at least a season to produce results. Here are four techniques for turning well-established turf into a bed ready for planting. Each method has its pros and cons, but all will get you one step closer to the bed you've been dreaming of.

Learn more: Low-Maintenance Alternatives to Lawns

1. Dig

This method produces quick, clean results and allows you to plant your garden immediately. But using a spade or fork to remove sod can result in a lot of sweat and sore muscles. If the sod is in good condition, you can use it elsewhere in your yard.

Water the area a few days ahead of time to make the soil easier to work. The soil should be moist but not soggy. Saturated soil is not only heavy but also susceptible to compaction, which leads to poor plant growth.

Cut the sod into parallel strips 1 foot wide using an edger or sharp spade. These strips can then be cut into 1- to 2-foot lengths, depending on the density of the turf and the thickness of the pieces. Next, pry up one end of a piece of sod and slide the spade or fork under it. Cut through any deep taproots, and lift out the precut piece, making sure to include the grass's fibrous roots. If the underside of the sod contains much loose soil, a fork may work best, as this soil can be shaken back onto the surface when the sod is lifted.

Roll up the strips if you skip the crosscut step, and keep peeling the strip back. Keep in mind, though, that these rolls will be heavy. If you are installing a large bed, consider renting a sod cutter. These steel-bladed, plowlike tools are more efficient than spades for large jobs, and they come in human- and gas-powered models.

Inspect your new bed's subsoil (and the underside of the sod if it will be reused). Once the sod is gone, look for and destroy potential pests, such as the larvae of May/June beetles. Remove any rocks, remaining clumps of grass, and sizable roots.

One drawback to sod removal is the significant loss of organic material, which greatly contributes to the health of plants. It must be restored as compost, as aged manure, or in some other form. Usually, topsoil must also be replaced. Some of it may be shaken out of the sod that was removed, but you will probably need more, especially if you need to raise the level of the bed.

Digging up grass may reveal harmful insects, such as Japanese beetle grubs, which you'll want to remove.

Pros: Permits immediate planting; avoids use of chemicals and loud power tools

Cons: Is labor intensive; exposes subsoil to weed seeds by eliminating vegetative cover; removes organic matter

Tip: Sharpen your tools before using them, and minimize muscle and joint strain by using ergonomically designed tools or tools of appropriate length and grip.

2. Till

One advantage of tilling is that the original organic matter is retained in the garden as the sod is turned under. You can add organic matter by forking or shoveling compost, manure, grass clippings, or leaf mold onto the sod before tilling. Breaking up sod with a tiller requires some muscle, but most of the work is done by the tiller's engine. Small tillers can usually handle previously worked gardens, but breaking up well-established sod requires a heavier, rear-tine unit and may require more than one pass. After tilling the bed, remove and shake the soil from any remaining clumps of grass.

A tilled bed can be planted immediately, but the process brings to the surface weed seeds that may germinate and cause problems later. You may also wind up inadvertently propagating some weeds like quack grass, which can send up new shoots from the small pieces of its chopped-up rhizome. Canada thistle does the same thing with its severed lateral roots. If you keep the soil moist and delay planting by a couple of weeks, you can pull, hoe, or otherwise dispatch these weeds as they emerge.

using a tilling machine to remove grass — Tilling lets a machine do most of the work, some of which is churning up thousands of dormant weed seeds.

Pros: Retains organic matter; is quicker and easier than digging; permits immediate planting

Cons: Is difficult on rocky sites and in wet or clay soils; turns up weed seeds; propagates certain weeds

Tip: Large tillers can be hard to maneuver. You will likely need to carve the edge of your new bed with a spade or edger, especially if the border is curved.

3. Smother

Perhaps the easiest way to eliminate grass is to smother it using plastic, newspaper, or cardboard. Depending on the time of year and material used, this can take several months.

Stretch light-excluding plastic over the lawn.
With the edges securely anchored, the temperature under the plastic will increase dramatically. The high temperatures and lack of light will eventually kill the grass, although they can also destroy beneficial organisms. Plastic can be covered for aesthetic purposes, but it isn't biodegradable and should eventually be removed.

Lay cardboard or newspaper over the grass as a better alternative. Cover these biodegradable materials with grass clippings, leaf mold, mulch, or compost to hold the layers in place, keep in moisture, and add organic matter. Lay down six to eight sheets of newspaper; use paper printed with black-and-white ink only, as colored ink may contain heavy metals. Newspaper and cardboard do not increase temperature as much as plastic, but they eliminate light, causing chlorophyll to break down. Once this happens, photosynthesis stops and the smothered plants die.

You can plant right away if you're using cardboard or newspaper. Just plug mature plants into holes that you have punched through the paper to the underlying soil.

man setting newspaper down on grass to remove it — Several layers of newspaper will block light, causing the grass to die. A few months later, the soil will be ready for planting.

Pros: Does not require the physical effort of removing or turning under sod; leaves original organic matter in place; does not disrupt soil structure

Cons: Delays planting up to several months; may kill beneficial organisms if using plastic

Tip: Lay down newspaper layers during the summer, and wet them to help keep them in place. The following spring the grass should be dead, and much of the organic matter you've added will have been incorporated into the soil by earthworms and other organisms.

4. Apply herbicides

I favor the first three methods, perhaps because I can see immediately any damage I cause (slicing through an earthworm with a spade, for example). Too often in our dealings with nature, unanticipated effects of chemical use have been discovered only later.

Choose an appropriate product, and carefully follow the directions on the label if you decide to use herbicides to kill your grass. Be sure to buy a product designed to kill grasses (not one specific to broad-leaved plants), and check the expiration date.

Don't apply herbicides when rain is expected or they may wash off plants and into the soil and nearby waterways. Also, avoid applying on windy days to prevent drift onto nearby plantings. Wear protective clothing, such as gloves, long sleeves, long pants, and a mask when applying herbicides.

Well-established turf may require more than one application. It takes several days for effective absorption of herbicides. Grass and weed seeds in the soil will not be affected and may germinate later. This option may be reasonable if you have appropriate equipment and follow safety instructions and application recommendations carefully.

Herbicides kill grass quickly, but it's often unclear what else they do in the soil. Some herbicides affect all plants, but others kill only grass, so choose wisely.

Pros: Is relatively simple and quick for gardeners experienced in herbicide use; makes it easier to remove or turn grass

Cons: Risks injuring or killing nearby plants; can result in environmental contamination, personal injury, or harm to beneficial organisms when used improperly

Tip: Follow label directions carefully, including those for product storage and disposal. Use only products specifically formulated for the types of plants you want to kill.