LASAGNA – It’s not just for dinner anymore

By Andrea Mull

Now that Fall is here, gardeners might falsely believe that the hard work is almost over. (Ha!)  This is exactly when we should be extra diligent. If we plan it right, the work we do now ― raking leaves, cutting back perennials, and emptying out that chicken coop ― can amount to a new garden bed for the spring.  And it all has to do with Lasagna – Composting that is.

Lasagna Composting (or Sheet Mulching), is a method of creating a new raised bed or adding to an old one. Layers are alternated between Brown (or Carbon) materials and Green (or Nitrogen-rich) materials, and allowed to rot all winter. By spring or early summer It turns into a nutrient rich, fluffy bed.

So how do we perform this miracle?
First, compile your “ingredients.”  Just like making real lasagna, you’ll need everything on hand ahead of time (at least for the first few layers, more layers can always be added later, unlike real lasagna). Materials you might consider include: straw (not hay), shredded leaves, any kind of Herbivore manure (horse, chicken, cow, rabbit), coffee grounds, grass clippings (no herbicide residues please!), and any trimmings from your perennials, vegetables, or yard (though if it is invasive or noxious you might want to just toss it in the trash). If you run the Greens through a shredder or lawnmower, or even roughly chop with a shovel, it will help them break up quicker. And of course food scraps (no meat or dairy!) can always be added, but keep buried so animals don’t come around. Also have on hand cardboard or newspaper; the more the better. 

Constructing the Lasagna Pile:

Wet the cardboard or newspaper and lay directly on top of the soil wherever you plan to have the new bed. No need to remove sod!  Just pry open little air holes with a spading fork, wet the ground thoroughly, and lay thick, overlapping layers of cardboard down. This layer will smother the grass and prevent weeds from growing up through your new bed.  Eventually, this layer rots and your new plants will send down roots.

Lay cardboard directly on top of the soil.

Make your bed is slightly larger than what you want the finished bed to be.  So, if you would like a 4x4 bed, maybe start with 5x5.

Now, looking at your “ingredients,” start making 2-4” thick layers alternating between Brown and Green.  A general rule of thumb is if it’s fresh, it’s green (Nitrogen).  If it’s dead or dried, it’s Brown (containing more carbon).  Exceptions include corn or sunflower stalks (treat as brown but chop first!) and manure (unless composted first, treat as green). Always water the brown layers, this helps with their decomposition.

Pile the bed twice as high as you’d like as it will sink. Cover with a deep layer of soil if you wish to plant in it immediately, otherwise, cover with a piece of plastic (to keep out excess rain), and allow to decompose all winter.  Occasionally, look under the tarp and water your pile, or leave it off for a while to allow for rain and air circulation. After awhile, it will start to look like dirt and you won’t need the cover.

Layer your ingredients, alternating between  Brown and Green.

This process is slow and could take as long as 6 months to fully decompose.  I found that if I start now (Oct-Dec), I can plant in it come May or June.  If you discover that there are still rotting materials in the bed, or if the surface is still lumpy and not smooth, cover with a 2” layer of finished compost or soil.  Plant or seed directly into this layer, by the time the roots come on, they can handle the courser materials below.

You'll  have a new garden bed by spring.

Once you have successfully built your first lasagna bed, you’ll never want to dig or rototill again!!