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The home page in this series on building raised bed gardens is Raised Beds Jim’s Way.
For my example throughout these pages, I’ll be “building” two side-by-side beds 3′ 6″ (3 feet 6 inches) by 12′ (inside dimensions). I’ll have a single 3′ walking path between them. There will be a 4′ walking path all the way around the outside as well. Finally, the beds will be made out of 2″x12″ treated lumber1. So, the length of the garden will be the length of the planks plus 8′. The width of the garden will be the total width of the beds (7′) plus 4′ for each of the two outside walkways, and another 3′ between each bed. That adds up to 7′ + 8′ + 3′ = 18′ for our width. The length of the garden is 12′ plus the two 4′ paths around the outside, or 20′ total.
Kill the Grass
If you intend to use a sod-removal device, you won’t need to kill the grass. So, you can skip this section.
The whole garden is 20′ by 18′. However, we won’t actually be planting that whole area. The paths around the outside and the paths between the beds don’t need tilling. However, you may want to kill the grass there so you can put down wood chips or paving blocks.
The first step is to kill the grass in the area of the garden. Use an herbicide (like Round-Up) to kill the grass. But, wear protective clothing and face protection to keep yourself safe.
If you intend to leave the grass growing on the paths, you only need to kill the grass on the actual bed locations. In our case, that would be two 3′ 6″ by 12′ rectangles. You may want to drive other stakes around these locations so you only kill the grass where you want it dead.
If you’re killing the grass on the paths, just use the stakes you’ve already placed as your markers.
Get a large piece of cardboard and have someone else hold it (who is also wearing protective gear) to avoid spraying the herbicide outside of the areas where you really want it.
Then wait a week or so until the grass has all turned yellow.
Till the Soil
Now that the grass is dead, it’s time to break up the soil. Grass, whether dead or alive, is incredibly hard to till. So, ideally you want to cut around the garden area and remove the grass as sod rolls.
If you don’t have access to a sod-cutting tool, you’ll have to use a tiller to tear up the grass. Give yourself plenty of time, because this is back-breaking work. Take frequent breaks, and make sure you drink plenty of fluids.
The herbicide you used above may have left residual chemicals in the soil that aren’t good for plants. Round-up goes inert when it hits soil, so that’s why I used it as my example. If the herbicide you use leaves hazardous material in place, you’ll want to remove all the soil containing grass and its roots.
Once the grass is removed or tilled through, continue tilling down to the maximum depth your tiller can dig down. Once the beds are in place, you won’t have the opportunity to ever dig this deeply again. So, use this opportunity to break up the soil and remove rocks and tree roots. However, you only need to till deeply where the actual garden beds will be. The paths, if you till them at all, are only tilled deeply enough to break up the soil so you can add wood chips, paving bricks, or whatever else you plan on putting down on the paths.
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