Turn Your Lawn into an Instant Garden with Sheet Mulching

Grass lawn being replaced by wood chip sheet mulch.

Do you want to turn a lawn, weeds, or a patch of bad soil into a garden bed with little to no digging? Sheet mulching is a method that does most of the hard work for you!

What Is Sheet Mulching?

Sheet mulching is one of the easiest techniques to start a new garden on top of your existing lawn or an area full of weeds. It can also be a quick way to turn your lousy soil into rich soil that’s full of life. Sheet mulching accomplishes three big garden tasks all at once. It removes weeds, improves your soil, and mulches your garden. As the name suggests, you simply create layers or sheets of organic material on top of the lawn, weeds, or soil, then sit back and let nature do the rest!

Sheet Mulching Components

The three components of sheet mulching are:

• Weed barrier – A layer of cardboard or newspaper to cover the lawn or weeds. Without light, the grass or weeds die and turn into compost.
• Compost – If your soil is poor, a layer of weed free compost will help improve it and provide the critters needed to help decompose the weed barrier. Alternatively, if you have lots of raw organic material available, you can create alternating layers of carbon and nitrogen from several inches up to several feet thick! If your soil is good, or you just want to smother the lawn or weeds, this step is optional.
• Mulch – A thick layer of mulch, at least 3” (5cm) deep, to suppress new weeds from being established and to retain moisture.

Young mango tree planted into lawn then sheet mulched.

Sheet Mulching Method

Here are the simple steps to sheet mulching:

1. Mow your lawn or weeds without the catcher. Just leave the clippings on the ground because they’ll add nutrients to the soil when they decompose.
2. (Optional) If your soil is heavily compacted, loosen it with a garden fork, but don’t turn it over. Stick the fork in the ground as far as you can, then move the fork back and forth to open the soil.
3. (Optional) Add any soil amendments (eg. gypsum, lime, nutrients), if required.
4. Water the area thoroughly to wet the soil and help the decomposition process. Avoid applying mulch on top of dry soil because the weed barrier can prevent water from getting through.
5. (Optional) If you have any organic material that might contain weed seeds, like cold compost, leaves, or hay, add them in layers on top of the ground, a few inches thick each. Water well.
6. Lay your weed barrier. I think big sheets of cardboard, used on pallets of paint at paint stores, are the best because they last longer, and are easier to put down. Large boxes from appliance stores are good too. Overlap the edges by 6” (15cm) to prevent weeds or grass from sneaking through any cracks where the sheets of weed barrier meet. Wet the cardboard thoroughly. Alternatively, use a few layers of wet newspaper, but tough weeds or vigorous grass might grow through.
7. (Optional) Put weed-free organic materials, like compost, on top of your weed barrier. You can also sheet compost by adding alternating layers of brown and green organic matter, like you’re building a compost pile. Water thoroughly.
8. Add your mulch layer and water again.
9. Allow the sheet mulch to decompose for weeks or months before planting, removing any grass or weeds that might pop through, or plant into your garden bed right away. Just pull the mulch aside, cut a hole in the weed barrier, and then plant into the ground. Put the weed barrier and mulch back around the plant, but leave a gap, don’t pile it against the stem to avoid stem rot. If starting seeds, plant directly into the compost below the mulch layer and water until established.