Sheet mulching, sometimes referred to as lasagna mulching, is a technique that involves layering different materials on top of a lawn to smother weeds, build soil, and conserve water the easy way. You may often see this term associated with “no-till” or “no-dig” as well, which refers to not digging up the earth, usually with the goal to not disturb the soil’s microbiome.
You can easily convert your lawn into a garden bed with the sheet mulching technique. Keep reading to learn how.
What do I need for sheet mulching?
You’ll need cardboard and/or newspaper and some kind of organic material like mulch, compost, topsoil, manure, straw, leaves, crop wastes, etc.
How do I start sheet mulching?
Getting started with sheet mulching requires large quantities of an organic material and cardboard. While you forgo the effort of digging and tilling, you trade it for the effort of moving and spreading soil/compost. But the beauty of this method is that it’s not too labor intensive once you get started, you just need to top-dress your beds with compost each of the following years.
Steps for Sheet Mulching
- Collect cardboard, remove any tape/stickers/staples as these will not break down.
- Lay the cardboard directly on the grass/weeds in the area that you want to convert to a garden bed. Make sure the cardboard is overlapping. This will keep light from getting to the weeds, thus weakening them until they eventually die.
- Once the cardboard is in place, wet it down until it becomes heavy and limp so it doesn’t shift around or blow away in the wind as you add layers of mulch and/or compost materials on top.
- Add organic material on top of the cardboard. You want this layer to be at least 3 inches thick.
Some people recommend using straight compost on top of the cardboard, but in our experience, this doesn’t work well when sowing seeds or planting tender transplants. We sell 2 soil/compost mixes. Both have our sifted high-quality top soil, which is then mixed with a compost of your choosing – mushroom compost or leaf compost. Both are great! Generally, we recommend the mushroom compost for vegetable beds and the leaf compost for flower bed.
Can I plant immediately after sheet mulching?
Yes. If you want to do this, we’d recommend laying the cardboard down, wetting it, and then topping that with 3-4 inches of a topsoil and compost mix. Where you want to plant, move the organic layer to the side to reveal the cardboard, you can then cut an “x” into that cardboard to reveal the soil below. Move the organic material back into place and plant.
What are the advantages of sheet mulching?
- Relatively easy
- It can be used to improve soil or add to existing beds and borders
- Requires minimum amount of equipment, material, and time.
Is cardboard biodegradable?
Yes, cardboard is biodegradable. When covered with organic material and kept damp, cardboard will break down within 6-10 weeks. When used with sheet mulching, cardboard really helps smother weeds.
What kind of cardboard should I use?
You can use pretty much any cardboard for sheet mulching. Just stay away from any shiny cardboard, as that typically means it has a plastic coating on it that will not break down. Also, make sure to take off any stickers and tape, as those will not break down either.
Where can I find that much cardboard?
Collect cardboard from family and friend. Ask restaurants, retail stores, schools, hospitals, and other establishments.
How much topsoil/compost should I use?
The quantity you need will depend on the size area you want to cover. We’d recommend laying the material at a 3 inch depth. Here’s a calculator to help you figure out how much you’ll need for your space.
Sources
https://extension.oregonstate.edu/news/create-vegetable-beds-lasagna-mulching
We source our cardboard from Costco. They already bundle it up for recycling so it’s flattened.
That’s a great idea – thanks!