Published on November 9th, 2011 | by Lynn Fang

Sheet Mulching: An Easy Way to Enrich Your Lawn or Garden

Sheet mulching is an organic gardening technique to enrich your soil’s natural biological fertility. It can also be used as a landscaping technique.

Why Sheet Mulch?

Suppress weed growth
Work less – no need to till
Improve nutrient and water retention
Encourage beneficial microbes and earthworms to grow
Increase soil fertility
Increase disease resistance
No chemicals necessary

Basic Technique

The concept of sheet mulch comes from the forest: well decayed compost is topped by a weed barrier of branches and leaves, partly decayed compost, and organic matter on top. The deep layering of branches and leaves blocks out enough sunlight to prevent weeds from sprouting.

Collect all the necessary materials you’ll be using, and lay them down in a day.

There are slight variations to how you can sheet mulch. The basic ingredients include:

weed barrier
compost
mulch
organic matter

Layer your sheet mulch as follows:

1. Organic Matter: Site Preparation

Mow and cut down all existing plants that you don’t want to keep. Layer them on top of the site.

Optional: Add a layer of compost to jump-start the decomposition process, at a rate of about 50lbs/100 square feet. By doing this, you introduce a plethora of beneficial micro-organisms that help to break down the existing plant material. If your soil is in need of other nutrients, this is the time to add other amendments, such as potassium or phosphorus.

Soak the area in water.

2. Weed Barrier

Pulling and killing weeds does not get rid of them, as they will come back again next year. Adding a barrier that blocks their access to sunlight can help prevent weed seeds from sprouting.

Materials to use: 4-6 sheets of newspaper, cardboard, burlap bags, old rugs from natural fiber, worn-out jeans, phone books, or other similar compostable materials. Don’t use plastic, as the weed barrier still needs to be permeable to air and water.

Wet your materials before laying them down. Overlap the pieces of the material so the ground is completely covered without any breaks, except where there are plants you want to save. If you have plants to save, leave a generous opening around the root crown to allow for healthy air circulation.

3. Compost

Add a layer of compost on top of the weed barrier to nourish new plants. If you do not plan to seed new plants, then you can skip this layer of compost.

4. Mulch

On top of the weed barrier, add mulch, which can include compost, grass clippings, seaweed, tree prunings, wood chips, straw, etc. This should form a fairly dense layer about 3－5 inches thick.

For more aesthetically pleasing covering, in conventional terms, use wood chips for the top layer.

If you are going to plant on top, just add soil and you’re ready to plant your seeds.

You will need to add mulch as the decomposition process continues.

If you want ornamental mulch, and do not want to plant anything on top, then you can replace the compost layer with mulch, so that a slower decomposition process occurs.

[CC Image by (Hayes Valley Farm) via Flickr]

Would you consider sheet mulching your lawn?