Garden Friday: Lasagna Gardening
Several autumns ago I got a great deal on a bulk order of 500 Lightning Sun tulip bulbs, and I had dreams of planting them along the front of my lawn in a new bed for a spectacular spring show. I imagined drifts of shocking orange blooms marking the boundary between private and public space, and of having plenty of cut tulips to grace my house and to surprise friends with a bouquet of joyful sprays on long stems.
Since our lawn sits back several feet from the road, the area I wanted to plant was often used as parking space for guests and was tightly compacted sand. I knew I didn’t want to dig that out and replace it with planting mix; the ace up my sleeve was the method of building a bed up in an easy layering technique described by Patricia Lanza in her book Lasagna Gardening. While the title may conjure a bed of vegetables and herbs ready to harvest for a classic Italian pan dish, it actually refers to the process of creating a planting bed by laying down thick pads of newspaper directly onto the sod or other area you wish to plant, and then layering grass clippings, peat moss, compost, leaves, manure, or any other organic, compostable materials on the top, to about 18 inches. After watering the resulting bed thoroughly, you should be able to nestle plants directly inside or scatter seeds on top, and as the layers compost over a season or so, you have a weed-free, nourishing (if somewhat strange-looking) new environment in which to grow just about any plant. I’ve seen pictures of flowers, vegetables, vines, and even rose bushes planted in lasagna beds that appear to be thriving, and I’ve read many positive reviews of the technique on online gardening forums.
My own experience was quite good. I detailed the first year of my lasagna bed, with photos, in a post on my long-neglected personal blog four years ago. To recap, the tulips that I placed directly on the newspaper before layering compost, horse manure, straw, and peat moss all bloomed fabulously the next spring, as did the cosmos seeds I sprinkled on during the early summer. The bed was weedier than I had hoped, probably because horse manure often has seeds in it, and because the rich mixture was an inviting landing spot for windborne seeds. The grass at the edge also marched onto the new bed more quickly than I had anticipated, which became a problem because pulling up the grass often pulled up and out chunks of the very loose mixture and exposed the bulbs; removing the big roots of my annuals (the cosmos in particular) during fall clean-up compounded the problem. My own lack of vigilance in keeping the grass at bay meant that by this past spring (year 5), the grass invasion was heavy enough that I decided to dig up the tulip bulbs as they sprouted and scatter them throughout the other flower beds.
In retrospect, I should have continued with adding layers each fall because as the layers compost, they settle, which means the bulbs I originally planted under 18 inches of material ended up being under only 4 inches by the next spring, resulting in shorter stems for the returning blooms. The good news is that the composted layers seemed to actually rework the sand underneath the bulbs and that first layer of long-disappeared newspaper; digging out the bulbs (which had now sunk below their original placement) was very easy and there was lots of nice dark soil left to amend other parts of my gardens.
I’m taking a break this fall, but next fall I hope to plant a new bed out front, using the same method, in preparation for putting up a picket fence. It will go in the same place it was before, right on top of the new grass that has currently taken over. I plan on changing two things: first, I need to acknowledge my laziness and figure out some kind of barrier to keep the grass from advancing onto the lasagna bed. Second, I’m going to look for an alternative to peat moss, since it is a non-renewable resource; I’ve read mixed reviews about substituting coir, so if it is hard to find or too expensive, I might just see what happens if I omit it from the layering process. Our horse operation keep us supplied with manure and straw, we have plenty of grass clippings, and our trees are maturing enough to give me at least one layer of chopped-up leaves, so my costs should be fairly minimal.
If you’ve had any experience with the lasagna method or have any questions, I’d love to hear them in the comments.