When I decided to expand my front garden plot by three feet, given that I wanted at least six inches of workable soil and the square footage was about 18 square feet, I realized I needed about 9 cubic feet of soil.
The first (and easiest) would be to just go and buy three or four bags of garden soil at the local center and place them on top of the area, poke holes on the bottom for drainage, and cut open the tops and plant directly in them. This has worked for gardeners like Barbara Pleasant. When I started looking at the cost of bags, though, it seemed that I would end up paying about $8/2 cubic-feet bag, or $36 overall for 9 cubic feet. How is it that dirt can be so expensive? Plus, having read how much soil is not just soil, that it has living organisms, nutrients, etc., I wasn’t too thrilled with planting in commercial soil.
Then, on a whim, I picked up a copy of Patricia Lanza’s Lasagna Gardening at the library on my way out. Lanza uses a method that’s also known as sheet composting, where you basically build your soil in layers like a lasagna, starting with laying down wet newspaper directly over the sod and then alternating different layers of grass, leaves, peat moss, and other mulching materials. Lanza claims that you can even plant in the bed immediately, but that she usually covers it with black plastic and lets it cook for 6 weeks, which is what I’m doing. After 6 weeks, some of the components will have broken down, and you can even dig below the newspaper to find softer soil to work with thanks to the earth-worm friendly environment you have created there.
Given our huge grassy yard that needs its first spring mowing and a bunch of unraked leaves that have built up around the perimeter of our yard, I did the math and figured that it would probably be cheaper and better for our soil long-term to try it this way.
The other reason I was so willing to try this method is that in my community gardening days in Oakland, CA, a fellow gardener, Greg, had found huge success with this method after years of struggling with bad soil. His lasagna beds were deep, dark, and crumbly, and everything that grew there seemed so happy.
Here’s the final so far, covered partially with plastic to help “cook” it.
The only concern I have at this point is that after moistening the bed and covering it with the black plastic, I found a white fuzzy layer growing on top after a few days. After googling it, I’m not sure if it’s a good or bad thing, but let’s hope that it’s good. I’ll probably pull back the plastic every now and then to make sure things aren’t getting too wonky in there.
So after having created my first bed, here are my thoughts:
- potentially better composition of soil – I don’t know how it will grow, but it definitely looks like better soil than other areas of my garden already
- no tilling required
- potentially less expensive (except for the peat moss)
- even though you don’t have to till, Lanza recommends mulching the leaves. Which requires raking them and having enough in the first place to put in your beds. I think doing this in the fall would be a much easier task.
- don’t underestimate how much you will need. I tried to follow Lanza’s recommendations for thicknesses of layers to get an 18-inch deep bed, but at the end it only came up to about 12 inches. I do think that part of that, though, is due to me wetting down the layers as I built, so maybe it would have been higher had I left them dry.
- it’s not that much cheaper – I ended up spending $27+tax, though I can honestly say that right now it looks like a lot more soil than I would have gotten for that amount in bags
I’m really looking forward to planting in this bed. I have an old wooden swingset structure connecting this bed and the other and a trellis net to put up on it soon. My vision is to grow purple runner beans up both sides and create a tent for the boys to play in there.