Lasagna Gardening, or Sheet Composting in the Organic Garden

The conventional approach to composting teaches organic gardeners that they need to make a large pile to generate enough heat to create decomposition. However, making a lasagna garden bed with sheet composting is desirable in that it doesn’t require a compost bin or a dedicated space in the garden to make soil building humus. Sheet composting also gives gardeners an easy way to create new flower or vegetable beds without the back breaking work of tilling or removing sod.

What is Lasagna Gardening?

Long before Patricia Lanza published Lasagna Gardening, organic gardeners were practicing this method of soil improvement with sheet composting. In this way of composting, gardeners layer organic materials to a depth of at least 18 inches and as great as 2 feet. These materials create a cold compost pile in situ, which gardeners can then use as new planting beds for flowers, herbs, and vegetables.

Creating the Sheet Compost Layers of a Lasagna Garden

The materials available to the gardener will influence the ingredients of a lasagna garden. Cardboard or newspapers usually form the bottom layer, as these heavy materials will stop the growth of grasses and small weeds underneath. Gardeners should add materials rich in nitrogen and carbon to the pile, just as one would add these to a conventional compost bin, to aid in decomposition, and to provide balanced nutrients to plants.

Some materials high in nitrogen gardeners can add to the lasagna garden bed include grass clippings, vegetable scraps, manure, and coffee grounds. Carbon rich materials for the lasagna garden include dead leaves, hay, straw, and sawdust. Gardeners who use fresh sawdust or woodchips in their lasagna beds should add this to the top, as mixing fresh chips into the soil causes nitrogen depletion as these materials decompose.

Is Lasagna Gardening a Weed Free Garden?

Weed free gardening is a hot topic, because this is the dream that all gardeners want. Pulling weeds in the early spring makes gardeners feel industrious after lying idle all winter, and spring weeding is easy when young weeds have a poor purchase in moist soil. However, gardeners can become neglectful in summer’s heat, and it’s easy to allow small sprouts to become young trees in August’s hardpan soil.

There is no such thing as a weed free or maintenance free garden, but sheet composting replicates the conditions of the early spring garden, year around. Thick layers of mulch and compost enable the soil to stay moist and crumbly, which makes weeding easy. The layered lasagna garden effect also stops sunlight from reaching weed seeds, which prevents them from germinating. So, while sheet composting doesn’t mean a weed free garden, it cuts established weeds and weeding chores in half.