For the area of yellow rectangles in the image below, the slope goes from shallow (on the left) to steep (on the right). The slope faces east.
Design Permutations
The first was a zigzag ditch (suggested by a permaculture designer) that was supposed to be for drainage, with little stopgaps and catchment pools on the way down. When I realized what he was designing and digging, I said, "Wait, it's for water? We don't get enough drainage here to fill it, even in the rainy season. I thought you were doing a hugel ditch."
So, we turned it into a hugel ditch and prepared beds above and perennial slopes below, but what a pain. You can't barrow-in organic material easily when you have a zigzag of raised ground.
So, I redesigned them as rows that went straight across (north to south), but with a curve, like a bow. I decided that would help catch water a little more and let it permeate deep into the soil. I gave up on the ditches and decided to berm using scrap wood. Massive pieces of scrap wood. I'd backfill uphill of the wood to make flat beds. In essence, terracing the slope using short wood retaining walls.
Then I realized the curve was pointless without swales (yup, the swales that the permaculture guy was essentially creating). Instead of focusing on water catchment (since I failed so spectacularly), I decided to focus on creating critter habitat, especially for snakes, so I thought laying the wood like a sine wave would create more "edge effect". What a pain to mow, though. And I tripped a lot.
Then I realized I should space the rows differently and have paths through the 100 feet of wood and backfill. This meant that all the wood had to move again. I also made the rows straight instead of wavy. :( What design permutation are we on? Yeah, 5.
Problem
I grew crops in the rows after that 5th design. Sadly, the super-wide beds were painful to plant in. My body is old. I only want to have to reach 1.5 feet or less.
Also, I hadn't had time to backfill to the point where the soil was level with the tops of the wood for the rows that were lower down on the slope (the deeper rows). And guess what I learned? The greater the difference in height between the wood and the soil, the colder the bed was in spring. In fact, there was a 2+ week difference between when the soil in the top-most row (closest to the house) reached and maintained 60 degrees F and when the soil in the lowest row reached 60. Why?
Every morning, chilly, humid air flowed down from the top and got caught and held by the exposed wood. Even if the uphill side of the bed had been raised, it probably still might've been a problem. We also have cold morning fog that moves up from the valley. I live in zone 8b, but the top most beds were more like zone 8a and the bottom was more like zone 7a.
What to do? I mean, coldframes, sure, but that's quite an expense.
New Idea
So now I'm toying with the idea of square raised beds, where the soil area is the size of a standard scrap square window or 2 rectangular windows (in case I do want to use cold frames). However, I want the squares to be rotated a quarter turn so that any cold air moving up or down the slope hits a point and flows around the raised bed. It has the added benefit of splitting and redirecting the super cold winter winds that blow north and south.
I did some calculations to compare new straight across rows of raised beds (designed 3 feet wide in order to fit scrap windows or plexiglass from Home Depot and be comfortable to reach across), with quarter-turned square beds (4 feet by 4 feet, otherwise I'd have to make a gazillion beds).
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