S Bengi wrote:If you were in a arid area I would say don't build any berms/raised bed even if it is only 12inches. If your area is prone to landslide and alot of heavy rains. I might also say that the 12inch berm (made of "sheet mulch") could be dangerous.
All that said assuming that you have a climate similar to me. I would say that an actual swale would be best, with a 2ft depression that is 3ft wide, with an elevated berm that is similarly sized. But, just your 12inch of sheet mulch that will compost down to 2inch after 3yrs and erode down to 1inch in 5years is better than nothing.
I am near Memphis, TN and we get a good amount of rain compared with most (50"+ annually, I believe).
One of my ignorant concerns was whether plants placed 12" above grade on sheetmulch would be able to access water at or below grade for a while. I guess the roots will reach and not find it hard to make it through the bulk materials, which will hold their own water from rain. Any added thoughts?
Also, I have never heard whether the end goal of sheetmulch is to see it compost down, at which point it's established and doing well. I had thought of doing composting in place. I guess you only need to do that a time or two in any given place before it's fine for a while / perpetually?
