Getting started in raised bed gardening is easy and offers a great many benefits to the gardener.
Raised bed gardening is an easy way to add more efficiency and beauty to your garden areas with little more than some good old-fashioned elbow grease and a little lumber. There are a number of reasons to incorporate them into your yard, if you haven’t already. Here are some of my favorites:
Create a pleasing design in your yard by installing raised bed gardens that function as architectural elements, delineating zones within an overall landscape plan. They can serve as focal points, direct traffic flow, or define outdoor “rooms” for eating, relaxing or entertaining.
• Easily condition your growing soil through the addition of compost and other amendments so you are not limited to what may be poor quality soil in a given location.
• Set boundaries for plants that might otherwise take over with elevated garden bed edges. Our friends have a chocolate mint bush that has taken over vast swaths of their garden, so when we took some cuttings for our yard, we made sure to plant them in a raised bed where they won’t get out of control.
• Provide structure to which you can attach trellises, hoop houses and row covers, allowing you to attain a larger yield and extend the growing season.
• Work with comfort in beds that have been built to whatever height works for you. This is particularly useful for people with limited mobility.
• Eliminate soil compaction, which can reduce crop yields up to 50 percent. Water, air and roots all have difficulty moving through soil compressed by tractors, tillers or human feet, and gardeners can avoid the problem completely by creating elevated beds narrow enough to work from the sides.
• Achieve a higher density of plants. Because you don’t have to allow areas to walk between rows of crops, you can plant vegetables closer together in raised beds than in traditional ground beds, resulting in a larger harvest from a given area of land.
• Drain off excess moisture better than ordinary garden beds. This is another advantage that helps the plant roots to breathe. In areas that have saturated soil, such as Florida and many areas of the South, raised beds may be the only way you can grow many types of plants.
• Create pest barriers against slugs and snails with the bed walls. Weeds also are less likely to pop up in a soil that you’ve blended yourself from compost, manure and other ingredients.
There are a lot of ways to build raised beds. My favorite is to find a way to work with what I’ve got. In this case, I had a pile of Douglas fir boards that I salvaged when a neighbor removed a fence, and they were still in perfectly good shape. The major challenge of this project was working on the slope where we wanted to situate the beds: This made the process a little trickier, but it came out great in the end. This type of bed is a great way to start making raised beds — just grab some planks and something to serve as a corner post.
• 8 Corner posts; 4-by-4; 2 or 3 feet
• 12 Long side boards; 1-by-5; 72 inches
• 12 Short side boards; 1-by-5; 60 inches
• Outdoor screws
• Spar varnish
1. Prep the reclaimed lumber. The most time-consuming part of the project was removing the nails from the lumber. This step was necessary, however, because we were going to run the boards through a planer, and ruining the blades is a real concern if any fasteners remain.
2. Evaluate the lumber. Once the lumber was de-nailed, we leaned it up along the wall so we could assess the quantity and lengths that we had to work with. Some of the boards had some paint left on them — we considered leaving it on, but ultimately we decided we were interested in natural wood finish all around.
3. Gather the corner posts. For corner posts, we cut up 4-by-4s that came from shipping crates. I made sure to leave them extra-long at this point, as they would be trimmed to their exact heights after assembly.
4. Plane the boards. Planing the boards is straightforward — it only took about five minutes to run the entire stack. You can skip this step if you don’t have access to a planer, but it really does make assembling the pieces easier. It also makes the boards look a lot nicer.
5. Cut the sides to length. We used a chop saw to crosscut the boards to length: We were making rectangular-shaped beds, so we needed an equal number of long sides and short sides.
6. Take the pieces to the site. On site, we laid out a few of the boards to get a sense of where to situate the beds and how it would look.
7. Assemble the front side. The easiest way to assemble the beds is to work in sections. I started by screwing the cross-pieces to the corner posts, starting at the bottom. The rest of the front side went together quickly. I recommend using screws that are coated for outdoor use to prevent corrosion.
8. Attach the bottom boards. We were working on a slope, which was a little tricky. To make sure things came together OK, I put the bottom boards on the whole bed, following the angle of the slope. There’s no need for math here — just push the bottom boards down tightly against the ground to make sure that no soil will be able to leak out.
9. Check the corner posts. It is important to keep an eye on the corner posts as you proceed — make sure that they stay plumb. I recommend sighting across them from time to time to make sure that they are parallel, because they can tend to shift around a little bit before they’re fully secured.
10. Complete the beds. We built the second bed in the same manner as the first, making sure to leave enough space in the middle to walk around. Working on a slope makes it important to start with posts that are extra-long. Often the posts ended up at different heights, and there’s no way to predict these dimensions beforehand. It is a lot easier to just give yourself more height than you’ll need and cut off the excess later.
11. Trim the corner posts. I used a chainsaw to cut off the tops, but a reciprocating saw or even a handsaw would work, too.
12. Square the beds. It isn’t critical that the final assemblies be square, but it is good practice to check. The best way to square a large object like this is to measure the diagonals and shift the bed around until the measurements are equal.
13. Varnish the boards. A coat or two of spar varnish is a good idea for two reasons: It will help the wood last longer, and it also brings out a lot of the wood’s natural beauty. For maximum durability, you might want to re-coat the beds every couple of years. It only takes a few minutes.
• 4 Long sides; 2-by-4; 96 inches
• 3 Short sides; 2-by-4; 89 inches
• 3 Long ends; 2-by-4; 48 inches
• 4 Short ends; 2-by-4; 41 inches
• 4 Optional trellis, legs; 2-by-2; length as desired
• 1 Optional trellis, spanner; 2-by-4; 96 inches
• 3-inch deck screws
I lucked into a supply of reclaimed redwood 2-by-4s early in the season, and I decided to use some of them to build a new raised planting bed. Redwood is a great choice for this because it is naturally rot-resistant. Because I had such nice material to work with, and because I could be assured that the bed was likely to last for quite a long time, I decided to use a joinery method for the corners that would be very durable and attractive. I like the look of the staggered joints, and this approach can be used whether you’re using 2-by-4 or 4-by-4 materials.
1. Figure out the size of the bed. I determined the size and location of the bed by setting out the first layer of 2-by-4s. When in doubt, start with lengths that are oversized and cut them down until they fit the space the way you like. I listed measurements in the Stacked Raised Bed Materials List for a good-sized bed, but feel free to adapt these steps to whatever size bed you want.
2. Cut the boards to length. The work proceeds quickly, and it only requires a couple of tools. The cuts can be made with a circular saw or a chop saw if you have one. My method for determining the required sizes is as follows (note that this bed measures 96 inches by 48 inches).
There are four different lengths required, and here are the terms I employ to keep them separate. Each box requires long sides, short sides, long ends, and short ends.
The long sides are the same as the overall length of the bed — 96 inches in this case. The long ends are the same length as the overall width — 48 inches in this case. The shorter components measure 7 inches less than the overall lengths (each 2-by-4 is 3 1⁄2 inches wide).
So, in this example, the short sides are 89 inches, and the short ends are 41 inches. This simple formula will work whether you’re using 2-by-4s or 4-by-4s, although if you’re using 2-by-4s set on edge, you’ll subtract 3 inches instead of 7 inches.
3. Attach the layers. I used 3-inch deck screws to secure each layer to the one below it, and I suggest spacing the screws about 12 inches apart. To make sure that the fasteners will hold up outside, you’ll want to use exterior-rated screws. This means that they have a special weather-resistant coating. Stainless steel screws also are an option, but they’re more expensive.
1. Attach the posts. I decided to mount a trellis to the back of this bed so I could grow things vertically. I used 2-by-2 lumber for the vertical components. I screwed it directly to the 2-by-4s on the inside corners of the bed.
2. Attach the spanner. The vertical components are spanned at the top by a 2-by-4. Since I didn’t have an assistant on this, I drove a screw near the top of the 2-by-2s that I could set the 2-by-4 on while I checked its position with a level. If one end was too high or low, it was easy to move the screw accordingly. Once the 2-by-4 had been leveled, I screwed it to the 2-by-2s.
3. Add more support. To add more visual bulk to the trellis, I added a second 2-by-2 in front of the 2-by-4. This isn’t functionally necessary — I just liked the look. I screwed the second 2-by-2 into the side of the raised bed.
Read more: GRIT blogger Paul Gardener shares how lasagna composting is a great way to jump-start your garden in the post, Low-Cost Lasagna-Garden Beds.
This material was excerpted with permission from Chris Gleason’s book, Building Projects for Backyard Farmers and Home Gardeners, from Fox Chapel Publishing.
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