Lasagna gardening — sometimes called sheet composting or sheet mulching — is an easy method for building a garden bed with little work. And it utilizes materials you may already have on hand. You can use this technique in the spring and plant directly in the “new” beds, or pile layers on in the fall and allow them to break down in the off-season.
Be sure to dive in and learn about composting, too.
Lasagna gardening seems like a “cheat”
When we first moved here, I wanted to get some plants in the ground right away, but knew that I’d need to improve the soil for better success in the long run. I’d read about lasagna beds (called such because the beds are layered, much like a lasagna) but had never tried them. This seemed like a perfect chance to it out.
Lasagna Gardening: Building the base
I started by raiding my recycle pile. Layers of flattened cardboard boxes, layers of newspaper, and even old catalogs form the base of the lasagna bed. I covered my planting area with a thick layer of these paper products, overlapping them as I placed them down, and then wet them thoroughly. This base layer was close to 1/2″ thick. Be sure to remove any plastic tape before using them in the garden.
Note: This is a no-till method of planting. You do not need to work the soil under the lasagna bed. You do not need to pull weeds. The newspaper and cardboard layer will smother any weeds that are there. Score!
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How long does it take cardboard to break down in the garden?
It depends a bit on the weather, but as long as the cardboard stays moist, it will break down within four to six months.
Adding a layer
My first “green” layer was ginger, which we have in abundance. I’ve used banana stumps here, too. You probably don’t have those “ingredients” on hand. Essentially you’re looking for something with a high moisture content and high in nitrogen. Vegetable scraps, grass clippings, or fresh manure can work well, too.
Now, must this be the first layer? Not necessarily. You can start with dry leaves or straw and layer a nice high-nitrogen layer on top of that. I start with the ginger (or banana) because it’s so chunky. I prefer the big pieces of material near the bottom of the pile and more “out of the way.”
This is a very forgiving method! You can use coconut coir here, or peat moss (though there are environmental issues with peat moss), or some sort of locally available organic product that holds moisture well to build a lasagna garden.
Layer number three (with a warning)
Layer number three was mulch. I used free mulch from our local green waste center, about 6-8″ deep. I also used free labor provided by my son. (UPDATE: We had the unfortunate experience of getting a contaminated load of free mulch that killed everything we put it on. I no longer use the free mulch, though I do still use free labor.)
You can use leaf mold or partially decomposed leaves in your lasagna gardening method. You could also use rotted straw from a stable, lawn clippings, sawdust, or any combination thereof.
Water the garden bed down after adding another layer.
Adding the final layer
The final layer was store-bought compost. In the future, I’ll have my own compost or composted manure, but at the time store-bought was the best I could do. The finished lasagna bed sat about 10″ high. Once it was complete, I planted seeds directly into the top layer of compost and watered them in. Days later, I had veggies growing. As the plants grow, the roots work their way down into the layers of the lasagna bed and the worms work their way up.
The layers decompose, improving the soil while supporting a crop of vegetables. I found that I did need to be judicious about watering, since the lasagna beds didn’t hold moisture as well as a soil bed would have.
Can I use the lasagna gardening method in raised beds?
I made my first lasagna beds directly on the ground with no containment. I’ve also used this sheet mulching method in beds bounded by big stones. It’s a pretty flexible way of planting. But you can also use this method in taller, more structural raised beds as you see above. Beds with raised sides offer an opportunity to add things like wood chips and shredded newspaper to the layers.
In a perfect world, I’d have put this lasagna bed together in the fall with more repeating layers and let it sit for several months until time to plant. But let’s face it: It’s not a perfect world and I’m terribly impatient.
As it is, the layers will compost as the seedlings grow. If you’re paying close attention, you’ll see that we doubled the size of the lasagna bed pictured at the top, but I neglected to photograph those stages of the sheet mulching process.
When my vegetables were done producing – about four months later – I pulled them out and dug into the lasagna bed. (I was so curious to see what I’d find!) While my puny soil was still far from perfect, just about everything I’d layered into the beds was gone. There were a few remnants and small pieces remaining from some of the cardboard boxes, but that’s it! Everything else in the lasagna garden had completely disappeared and become part of the earth.
This sheet mulching method is an excellent way to get a jump on garden season, too. In the fall, follow this method using several layers of material but skip the seeds. Mother Nature will do her magic during the cold winter months and you’ll have a beautiful bed ready to plant in the warm weather.
Originally published in July 2014; this post has been updated.