mulching
sheet mulch a new bed
layer organic matter like a lasagne over unbroken ground and let it compost in place into a rich bed.
sheet mulching is composting where you stand, building a bed in stacked layers directly over grass or weeds. over a season the whole thing breaks down in place into deep, dark, worm-worked soil — no digging, no heap, and a thick smother that clears the ground beneath as it builds the bed above.
the method
- 01
feed the soil first
mow or trample existing growth and water the ground well. a thin scatter of compost or manure on the surface first wakes up the soil life that will do the composting.
- 02
lay the weed barrier
overlap plain cardboard or thick wads of newspaper across the whole area, seams well overlapped, and soak it. this is the light-blocking layer that smothers what is beneath.
- 03
build the layers
alternate carbon and nitrogen just like a compost heap: straw or dead leaves, then grass clippings or manure, then more carbon, and so on, building fifteen to thirty centimetres tall. water each layer as you go.
- 04
cap it and let it cook
finish with a few centimetres of compost or fine mulch as the top layer. left over autumn and winter, the stack settles and composts down into a planting bed by spring.
- 05
plant into pockets, or wait
for an instant bed, open a fist-sized pocket of compost down to the cardboard and plant a transplant straight into it. or let the whole thing finish and plant into the finished surface next season.
field notes
- build it in autumn from the year's fallen leaves, spent crops, and grass — the materials are free and abundant exactly when you want them.
- make it taller than you think; a sheet mulch can lose half its height as it settles and composts.
common mistakes
- ×too little carbon, so the stack turns into a wet, smelly slump. keep the browns generous.
- ×thin or patchy cardboard that vigorous weeds push straight through.
plants for this practice