A friend phoned the other day for advice on making a new garden in a sunny spot in her lawn. Knowing the labor involved in turning over a new garden, especially one planted into less-than-optimum soil, I suggested lasagna gardening. The term refers not to what will be growing there – although you can certainly plant the veggies and herbs you’d use to make lasagna – but to a method of prepping the space without ending up in traction.
Lasagna gardening, aka sheet gardening, simply means that instead of going down into the soil with a fork or spade or rototiller, the gardener layers compostable materials on top of the spot that is to become the garden. No tilling, no weeding, no digging up sod.
The layers will cook down over time to smother the weeds and turf. While the layering is best started in fall so the mix has time to meld together rather like the casserole for which it’s named, you can start any time of year. Lasagna gardening is an easy way to simultaneously create a garden bed and amend its soil since the layers of organic material you’re putting down add tilth and nutrients.
The principle in lasagna gardening is sister to a constructed compost pile. Yet unlike a compost pile, you don’t turn it. You let it just lie there and do its thing, becoming a rich planting medium. As with a true compost pile (as opposed to a midden, which just gets stuff flung onto it), it works best if you layer according to the best composting principles.
To create a lasagna garden, start by marking off the space. Then lay down a layer of corrugated cardboard or several layers of newspaper (soy inks only, no glossy pages) right on top of the turf. Worms love this stuff and tend to congregate beneath it, a terrific addition to the whole enterprise. Water down the first layer, in part so it will stay in place, in part so it will start to decompose right away. Follow this with a brown layer (straw, leaves, sawdust, cornhusks, dry brown weeds, etc.) then a green layer (fresh grass clippings, manure, kelp, coffee grounds, human hair, blood meal, crushed eggshells and more) with moisture added as necessary. (Rather like cooking.). Brown layers should be approximately twice as thick as green layers since they are generally lighter and enable air to get in, a necessary element. Continue lasagna-fashion until you have a bed about two feet tall. It will rot down and sink in a good deal over time. Once it’s fairly well composted, you can stick a fork or spade in and plant.
As with a compost pile, don’t add diseased plants, weeds with seeds, any fresh sewage, kitty litter or pet feces, meat scraps, bones, or cheese or grease or fats, which keep the things they coat from breaking down and attract animals. There is a list of the things that comprise ‘brown’ and ‘green’ elements in a couple of the links below and also in Patricia Lanza’s book, Lasagna Gardening (Rodale), which you can order through Compleat Bookseller.