If you’re building a bed over concrete, place a 10cm layer of dry branches onto the concrete to allow air into the bed, and head to Part 2.

If you’re building over the earth that has few weed problems, you can proceed straight to Part 2.

Part 1: the ‘sheet mulch’

Sheet mulching is where we create:

• A physical barrier to weeds with a biodegradable layer — in this case, newspaper or cardboard
• Anaerobic (low oxygen) conditions under the barrier kill the weeds

Now in general we don’t want anaerobic conditions in our soil. They stink, and they kill plant roots. But you have to break a few eggs to make an omelet, right? Well in this case we’re making something more like a rotten egg funk.  (Don’t worry though, it will be underneath the newspaper so you won’t smell it!)

This is a one-time-only establishment technique. It’s best done in warmer months, as this helps create the conditions that we need to rot the weeds.

1. Slash the grass or weeds
2. Over the slashed area, sprinkle with blood-and-bone or chicken manure, and water it in. This will create an anaerobic skank. And it will also help the newspaper break down over time.  Think around a good handful or two per square meter.
3. Soak your newspaper or cardboard in water (e.g., in a wheelbarrow).
4. Cover the area with thick layers of damp newspaper (at least 6 pages thick — more if any runner gasses like a couch or kikuyu grass are present), overlapping by 10-15 cm.  Be thorough!
   

Tip: bike shop cardboard can be great as it’s huge and you get the job done a lot faster.