Browsing YouTube today, I came across an interesting video. These guys take sheet mulching to a whole new level. I didn't keep count, but this bed has at least a dozen layers in it. What would be the advantages/disadvantages to all this extra effort?
Woah lol. I'm not sure if that should be sheet mulching on steroids or hugelkultur on crack. I'd say the advantage is that it breaks down into soil very quickly, which could also be a disadvantage vs hugelkultur. I don't think there's much advantage vs regular sheet mulching, since you generally use sheet mulching to cover larger areas anyway, you don't really want it 3 feet high, or at least it isn't very practical.
Wet the cardboardbefore putting it down to make sure it's soaked through and not just wet on the surface.
He added worms that he had harvested, and he added them early, burying them under a lot of material before he was done. I was surprised by this.
He also added some things that aren't normally mentioned in sheet mulching, like gravel and clay. After a while, I started to get the impression he was just padding the video by finding more things to add.