Composting is a rich and fertile topic, and there is always something more to learn. I got my most recent lesson at a presentation on Sheet Mulching by Kate Heiber-Cobb, a Permaculture Designer and founder of the Madison Area Permaculture Guild.
The beauty of compost!
Heiber-Cobb says that sheet mulching is also called a compost comforter, which I thought better describes the process. What gets piled up is a lot thicker than a sheet. It’s more like a Seven-Layer Salad for your soil.
Sheet composting is a no-dig, layered-mulch method of turning lawn turf or other vegetation into a rich and vibrant growing medium without first removing the existing ground cover.
The premise is that digging out the targeted plants is not only unnecessary – it is deleterious and detrimental.
Tilling will disturb the microbial community already happily living there. What we might think of as plain dirt is actually an interactive cosmos of micro-organisms insects and earth worms. It reminded me of Horton Hears a Who. There is a whole tiny universe going about its beneficial business in the soil.
Just weeks ago, Doug and I laboriously tilled up an area to prepare it for future gardening, and now I’m thinking we could have saved ourselves a lot of effort and approached the process more gently.
Heiber-Cobb says fall is a great time to do sheet mulching, if you want to have a new garden spot next spring. If it is done right, it will be ready to plant.
But tucking your new bed under a compost comforter requires gathering a lot of materials. I am going to start working now on accumulating so I can quilt up a compost comforter in the spring. Then we can compare how the tilled and non-tilled beds do.
You can find a step-by-step guild to Sheet Mulching here.
Basically it involves alternating 5 layers of carbon and nitrogen, the two elements that activate the composting process and turn all the materials into rich, moisture-holding soil.
Think of nitrogen as the green, fresh, wet materials, and carbon as the dry, woody stuff. A good ratio is 3 inches of dry leaves or straw to one inch of compost or manure.
Here’s how Heiber-Cobb does it.
1. (nitrogen layer) Start by cutting the lawn or other plants and leave everything lay where it falls. Add some concentrated compost to jump-start microbial activity. Heiber-Cobb recommends 40 pounds per each 100 sq. ft. That’s a layer about 2 to 3 inches thick.
2. (carbon layer) This is the biodegradable weed barrier. Use cardboard or newspaper. Make sure there are no gaps in this covering, and make it thick. If you are using newspaper, use 6-9 sheets thick. (don’t worry about color photos. It’s usually soy ink these days). If you are using cardboard, get the biggest sheets you can find, but make sure you remove tape and staples. (If you do this in the spring, you can cut holes in the cardboard and set your plants right into them.)
3. (nitrogen layer) A good manure layer comes next.
4. (carbon layer) Now add a layer of shredded paper or straw.
5. (nitrogen layer) Finally top it with a layer of kitchen compost and garden soil mix.
This sounds like a lot of work, but a great way to generate a healthy, productive and ultimately low maintenance ecosystem. I’ve always loved introducing organic matter into any soil I am responsible for, but this system seems both more organized and more effective than my past efforts. So, we’ll see!
How do you like to enrich your soil?