Sheet mulching. Also, sometimes called “lasagne gardening” or “composting in place.”
There are few garden practices I would call life-changing, but this one most certainly is.
First of all, what is it?
Sheet mulching is the practice of layering organic material onto the surface of the ground, rather than digging up or tilling.
It is an especially good idea for any area where you would like a new bed: for instance, turn an area of weeds or sod into rich soil for planting without ever picking up your shovel or an herbicide.
How do you do it?
- Cover your area with a single layer of ordinary, brown cardboard (plastic tape removed) or a thick layer of regular (non glossy) newspaper. Wet well with a garden hose.
- Add at least six inches (a foot would be even better) of organic material on top of the cardboard or newspaper. I love to use mushroom mulch (a rich by-product of mushroom farming), but you could use shredded bark, chopped leaves, straw (not hay), compost, or composted manure. Woody toppings will take the longest to break down.
- Time. Follow those two steps in the fall, and you will have a bed ready for planting in spring. But feel free to do it at any time. You’ll know when the bed is ready: over time, the cardboard or newspaper will break down, but not before the grass and weeds underneath have died and decayed and fed the soil.
Why does it work?
Sheet mulching mimics nature by building soil from the top down. Picture a forest: why is the soil beneath the trees such rich hummus? Because year after year, the leaves fall, decay, and–top down–the soil grows richer.
THAT is the power of sheet mulching.