By David Gabbert
The Growing Together Community Garden was able to fill 30 metal raised beds (2′ wide, 8′ long, 1.5′ height). The raised bed would need 24 cubic feet to fill it entirely. This can be rather pricy, especially when you have 30 to fill. Luckily, there is a method to reduce the cost to almost free, and help improve the soil health.
To fill the raised bed, it’s good to think of it in three parts: bottom, middle, and top.
For the bottom section, you start by removing the grass and other plant materials to almost bare dirt. You’ll then want to cover the ground with a form of weed barrier, either landscape paper (as seen in the picture) or landscape fabric, which works great for this. The advantage of paper is that it will organically break down over time, allowing worms to come and go as they please. For a free alternative, you can use old newspapers or cardboard. Be sure that neither has color ink or wax coating.
After the weed barrier is placed over the ground, you’ll want to move on to the middle section. You’ll want to start by placing large logs first, next you’ll want to add smaller limbs to fill in the gaps. Once the bottom half of the raised bed is filled with logs and sticks, you’ll want to move onto the next section of the raised bed.
At this point, half of the raised bed should be filled with logs, sticks, and some sort of weed barrier. The top part will be a lasagna-style dish, with many layers. Start with some sort of compost (worm casting, vegetable compost, and/or animal manure. If animal manure is used, be sure it is at least 180 days old before being used. You’ll need to cover the wood by at least an inch. Once this is completed, you’ll add 1-2 inches of plant organic matter, which could include: grass clippings, straw, weeds removed from other rows, pine needles, and/or fallen leaves. Now you repeat these steps until 3-4 inches remain to the top of the raised bed. You’ll need to add soil for the remaining part. You can either purchase raised bed soil mix, or you can call around and see if anyone has affordable topsoil they can deliver.
The raised bed should be almost completely filled. Over time, the raised bed will compress due to the logs and sticks decomposing. You’ll then want to add more soil as the raised bed compresses. Be sure the soil is covered year-round with some sort of mulch. This keeps the soil from hard panning, reduces nutrient runoff, and reduces the amount of water required throughout the growing season.
