What kind of material is best for sheet mulching?

Paper materials are often used for permanently sheet mulching a space with organic material and some options are far better than others.

We first thought cardboard was the go-to sheet mulch material since it was often thick and big. Little did we know at the time, it isn’t the only best option out there. After testing several types of sheet mulch material we’ve come to a conclusion.

The best sheet mulch is any material thick enough to block out light, is easy to work with, and is clean of plastics or tapes with chemical residue. The best permanent sheet mulch is compostable material. Temporary sheet mulch can be inorganic, preferably a long-living plastic such as vinyl.

To learn more about temporary sheet mulch and material head-over this way. To learn more about organic sheet mulch materials and the adequacy of each, continue reading.

Paper leaf bags, newspaper, and cardboard are our top picks. They are reused materials, are free to find, and can easily accumulate in large quantities. Many people also use fresh paper on a roll. Rolled paper is practical for large spaces but is costly to buy and often thin.

This article was originally published on foodforestliving.com. If it is now published on any other site, it was done without permission from the copyright owner.

Related: Best Way to Remove Weeds to Restore a Large Area

What is the easiest sheet mulch material?

Even our top-pick sheet mulch materials have varying ideals but one outshines them all. cardboard, paper leaf bags, and newspaper can all work effectively. The new question is which one is the easiest to find and easiest to employ?

Paper leaf bags are the easiest sheet mulch material for sourcing and workability. In autumn, check the city schedule for leaf pick-up, and drive around to gather full paper leaf bags before the date. Empty the leaves into a pile for compost, flatten the bags out, and use them where needed.

The limit on leaf bags you can gather basically has no sky and free compost is a bonus.

When compared to newspaper, paper leaf bags are an adequate and consistent thickness and a single sheet covers more ground at once. Paper leaf bags also have a longer life span than newspapers, but not cardboard.

When compared to cardboard, paper leaf bags are free of plastics, staples, and adhesives and shape to the ground. When regular mulch is shoveled on top of leaf bags they compress to the ground and leave fewer rodent-hospitable tunnels.

Gaps under cardboard are less alluring if the ground is quite flat. Also, inviting habitat isn’t necessarily the worst thing. If predators are abundant, they become a functional addition to a good system. In this sense, the gaps become a treasure trove of food for snakes (if you have them!)

Repurposed cardboard can become a lot of work removing labels but it may be worth the longer lifespan.

Newspapers are easy too. They require more of them to get an area covered and the biggest challenge they pose is proper overlapping. They also decompose the quickest. Plenty of newspaper can be collected in stacks each week at your local nursing home—just ask.

How many layers of cardboard do I need for sheet mulch?

The effectiveness of sheet mulch depends on how a particular material is laid. The cardboard is made thick enough for light to be impenetrable. The gaps between laid cardboard sheets are the only opportunity for failure.

One layer of cardboard with 4 inches of overlapping will smother weeds and prevent any from growing through. Cover the cardboard with regular mulch to prevent shifting, or use rocks to hold them in place.

We have also found that a mix of sheet mulch materials is helpful around tricky areas. Cardboard is great for wide or long uninterrupted coverage, and newspaper is easier to customize around the base of plants. Be careful not to put sheet mulch too close to the trunk of any plant.

How many layers of newspaper should I put under mulch?

Stacks upon stacks of newspaper are easy to find but can easily be laid too thin when used as sheet mulch. You’ll need plenty of paper for total shade.

For any paper sheet mulch, a good rule is a minimum of 5 sheets thick. To be sure, hold your layers up to the sun. If you see through, add more layers until you can’t. Lay squares (or rectangles) of newspaper beside one another, and overlap each crevasse with a second layer.

Will weeds grow through wet newspaper?

Not only do your newspapers need to cast dark shade—but have to be strong against plants that may attempt to grow through.

Established weeds will grow through wet newspaper if it is laid too thin. Plants cannot grow through thick newspaper even when wet, and especially when covered by regular mulch.

Newspaper breaks down rather quickly when compared to paper leaf bags or cardboard. This is a main disadvantage of newspaper unless you top it with several inches of regular mulch.

Established or persistent weeds may have root systems that outlive newspaper. Insistant weeds like quackgrass can even live in darkness long enough to spread beyond the width of a large cardboard sheet mulch!

So it’s best to remove or substantially disturb as many established weeds before sheet mulching with newspaper.

Don’t shy away from doing a double layer either. When sheet mulching with newspaper we lay them side by side, and stack a staggered second layer like bricks. Double the darkness, strength, and time until decomposed.

How long does it take for newspaper to decompose?

Like any organic matter, newspaper decomposes fastest during the growing season when ecosystems are active. Dormancy freezes life to a stand still and nothing happens until nature’s white slumber wakes.

It takes newspaper between two and eight weeks to decompose in spring, summer, or autumn. Newspaper can remain intact all winter, and continue to decompose in spring.

Early spring is the best time to knick weeds in the bud, before the bud! Stop em before they even get a chance to start with well-timed sheet mulch.

When to lay newspaper sheet mulch

For early spring smothering, lay newspaper as close to the first snowfall as possible. As winter begins, freezing and thawing contribute to decomposition. However, the paper will freeze for long enough to remain intact before they break down and become ineffective. 

Weeds will be slower to spring back to life under mulched newspaper sheet mulch. Natural mulches tend to keep the ground colder for longer because no sunlight reaches the ground. The sunlight will reach the uncovered soil around the 6-inch base around your plants earlier and liven them up well before weeds.


While Rachelle's hands are clean for the keyboard, she enjoys writing and designing creative content and resources. You will most likely find her outside planting a cabbage, foraging berries for breakfast, and collecting herbs for year-round tea or making food.

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