Some of my best memories growing up are of my grandfather teaching me how to plant a garden between the ages of 4 & 7, and during that time, being sent out to gather cucumbers, tomatoes, okra, corn, beans, eggplant, etc. for the big, vegetable-laden meals grandmother would make. Life pulled me away from that healthy lifestyle for a while, but I've gravitated back with the help of my Dad, my wife's "foster Dad", John Kohler of www.growingyourgreens.com, and my stubborn will to learn how to do everything that we as a society have handed to others over the last century, and which we've steadily watched get higher in cost and lower in quality. I've only just begun, but I've never felt so satisfied as I've learned to work the soil, as it was originally intended for us, cutting out all of the middle-men. It can be hard to get started growing if you are on a tight budget and you are currently buying expensive produce to strive for good health, so it pays to learn some cheap and free ways to do things. You don't have to buy expensive pots, plants, and soil to get started, if you have a little patience and resolve to enjoy the journey over the time it may take to get established. This instructable is for one way I found to save money on a garden.
Raised beds offer a few benefits over direct sowing in the ground. First, it will save your back in the long run. You might not appreciate this if you've never had back problems, or haven't hit 30 yet, but back injury will affect your life in a major way, should you be added to the growing number of those afflicted. Second, raised beds can help the growth of root vegetables dramatically, as since you are controlling the depth & type of soil that goes into the bed; you can omit pebbles, rocks, sticks, roots, clay, and other debris that obstructs or chokes healthy roots, and you can fill to a depth that is appropriate for your plants, as opposed to having to borrow or buy a tiller to get a good depth of well-worked soil in your ground. The third and original reason I decided to build raised beds is protection from small pests, particularly rabbits & turtles, but potentially many more. Also, for many people, raised beds or pots may be the only option, if they have little or no land of their own. This design is simple and is intended for use on open, untilled ground (as opposed to a patio or deck).
At least 14 wood screws (#9, 1-1/2" - 2" long, depending on thickness of your pallet slats) - I used 28 for extra strength
Screwdriver or drill driver
Drill & 3/32" drill bit
Hammer & small prybar
Clamps (recommended, but can be built without, if you have a helper)
Needlenose pliers (recommended if having trouble with nail heads breaking)
Hand saw or circular saw
Black plastic sheeting (the thicker the better)
Landscaping fabric (optional)
Before we begin, I must bring up safety concerns. There are countless types of pallets used in countless industries. Many of these pallets will be treated with toxic chemicals, or will have come into contact with toxic chemicals. I'm no expert, but there are resources out there to help you identify the safest pallets, such as minnecrapolis' instructable: (https://www.instructables.com/id/How-to-determine-if-a-wood-pallet-is-safe-for-use/). Or if you want to go more in-depth, check out schnurrbart's instructable: (https://www.instructables.com/id/The-Pallet-Bible-A-Guide-to-Finding-Inspecting-and/). Great stuff. Having said that, for this project, I plan on avoiding toxins by applying a thick plastic sheeting to the interior of the raised bed. As I don't know how effective this will be, I strongly advise you to take schnurrbart's or minnecrapolis' instructables seriously before you use your pallets for this project.
Step 1: Procure Pallets
I'm fairly new at this. I'm maybe a few years in at this point on procuring and building with pallets, but I've learned that there are businesses out there which receive products on pallets, the disposal of which is a nuisance to them. I'm lucky in that I work with one of them, so I can get satisfactory pallets from time to time. But I've found that if you keep an eye out, you can find businesses that don't want their pallets, by simply driving around back and looking to see if they have them sitting out in their loading area or dump area. If you see them, simply ask. Grocery stores are a great resource, if they will give you some of theirs, as they should be food safe. But don't trespass or steal! Some people and businesses value their pallets as much or more than us makers do, and reuse them for their business or sell them. There are an unlimited number of sizes of pallets, but I typically get only the 36"X40" size, as they are about the largest that will fit in the back of our Subaru with the seat folded down (we can fit about 4 at a time in there), are great for many home projects, and they are the most readily available size, at least for me. I don't want to get too attached to a size I can't regularly find. For this project, I am using two 36"X40" pallets. Also for this project, it is best to get pallets with the top slats as close together as possible and with an even number of slats.
Step 2: Gather Tools and Other Materials
I'm recommending the black plastic shown. However, since I am confident that my pallets are safe, I am using heavy duty landscaping fabric, for improved drainage and aeration (but mostly because it was free, and I need the black plastic for a 12' treated pine raised bed I am also building). The screws in the picture are my favorite. The torx style head prevents stripping, and the stainless material can be used over and over, as they will not rust.
Step 3: Remove Middle Slats
On the bottom of the pallet, remove the middle slat with a prybar. If your pallets have an odd number of top slats, you will need to remove the middle top slat with a prybar, as well. If your pallet has an even number of top slats, your work will be much easier. Be patient and take your time to loosen all of the nails gently. It can be hard to remove the nails and the heads may pop off and/or pull through the slats, but to prevent damage to your saw in the next step, you will need to remove as many as possible if not all of the nails, and not simply beat them over with a hammer. First, pry gently under each side of the slat at each runner, working from one side of the pallet to the other, and starting again where you began, to loosen each connection more. You want the slat to do the work of pulling the nails out, if possible, but if you jerk too forcefully on the slat, you may just have the nail pull through it. I find that a small double-end prybar works much better than a hammer. I use needlenose pliers for the difficult headless nails that get left behind. You can bend the shaft in half and then use it as a handle with the pliers to twist the nail back and forth, while pulling.
Knock the nails and pry them out of the middle slats, and set the slats aside for later use. Though it would be easier work to have an even number of slats, the end result will look better if you have an odd number of top slats, as you will see.
Step 4: Cut Pallets in Half
Measure to the half-way point of the pallets and mark lines across each runner, in between the middle two slats on top of the pallet. Mark the bottom of all of the runners in the middle. Use your saw to cut the pallets in half. Be very careful while sawing, as you may run into nail fragments. Wear safety glasses, and don't use a nice blade for the job, unless you know for sure you won't run into any nails. If the dividing line is right on top of a nail, simply saw to one side of the nail, or other. There's no need to be extremely accurate with this, as it is just going on the relatively soft ground anyway. My circular saw is not big enough, depending on the slat thickness to get all the way through to the middle from the top side, as you can see in one of the pictures. If this is true in your case, you can finish it off with a hand saw, or just give the pallet a good swift kick to break the remaining wood connecting the two halves.
Step 5: Fasten First Corner
Make sure to build with pallet halves from the same pallet located across from one another, as the layout shows. So, each corner will have half of one pallet connected to half of the other pallet; but not two halves of the same pallet together. This will ensure the best symmetry and squareness. It will not be perfect, no matter what, but this will provide the best outcome. Attach the two halves together loosely with clamps, tap into squareness and flushness, and then clamp tightly to drill the pilot holes. When attaching the ends of the half-pallets that don't have the bottom slats attached (the part that used to be the middle), make sure to allow for the thickness of the missing slat. As you'll see later, I wasn't paying attention and screwed one section together out of square and had to go back and fix it. The first time I made one of these, I only used 8 screws (2 for each corner), as that's all I had, but for this project, I used 4 for each corner. For the top of each corner (where the bottom slat is still attached), drill the pilot holes inside the one pallet, and into the other, as that is the easiest way to fasten. For the other fastening points, use the optimal method of drilling and fastening through the slats and into the thick runner.
Step 6: Fasten Other Corners Together
Clamp another half-pallet on an open end of what has already been assembled so far, being sure to adhere to the layout. You could opt to lay these out in a spiral pattern if you like, but the layout I decided upon allows for a bit more width for my tomato plants. I didn't start getting pictures again until I put the last side in. It was hot out and I was probably getting delirious from dehydration. You can see in the second picture that I made a mistake in regards to squareness, as I mentioned earlier. So I remeasured everything to put the right amount of space at the bottom of each corner.
Step 7: Attach Black Poly Sheeting
I forgot to get pictures of the entire plastic-stapling process, but you guys get the picture. Loosely fit your sheeting inside your frame, and clamp loosely. Staple along one corner, and pull slightly taut to the other corner and fasten. If you are unsure of the safety of your pallets, I advise only stapling along the top and bottom of the raised bed, to prevent making passages for contaminates to leach into your soil. I had some free scraps of landscaping fabric that I pieced together into mine. You want to leave about an inch or more margin at the top. You need excess at the bottom to protect the wood from microbes which will break the wood down faster, but don't worry if you have seemingly too much excess. You can see in the third picture that I folded my excess up into the bottom, once I turned it over into its place. If you don't have a lot of excess and you want to be extra-thorough, you can put a sheet of landscape fabric in the bottom to help protect from weeds, but they probably won't make it through the depth of soil that we will be adding anyway. I didn't worry about that gap in mine. I wouldn't put plastic in the bottom, but if you want to, make sure to poke holes in it for water drainage. My other raised beds have more gaps than this one, and I've not seen any weeds in them after 3+ months. Cut the corners of the plastic, so that you can fold the margins over the edge of the wood. This will help the wood last longer, and also get the edge of the plastic out of the way, where it won't get caught and ripped. Staple them down.
Step 8: Add Top Planking
Now, take those two (four if your pallets had an odd number of slats on top) slats that we set aside earlier, and install those on the top of your raised bed to finish it, and offer a surface to lean against while tending your garden. Fastening into end grain is not optimal, but in this application, it will be okay--just be sure to put a bit of angle on the screws for a more secure connection. This step is highly recommended. I didn't do it with my other raised beds because I couldn't successfully remove the bottom slats from those pallets without destroying them, as they had SO many nails in them. It is harder to lean against those. Since I only had two slats for this, I just tried to decide from which sides I would be doing the most work. I may find some more wood to complete all of my beds this way, as it looks a lot better and less pallety.
Step 9: Add a Layer of Fill Dirt
The beauty of this simple design, is that it gets your work up off of the ground. However, we don't want to waste our precious soil filling up the lower volume where most garden plants will never reach. So we need two full wheel barrow loads of any old dirt. Before adding dirt, check for levelness and add big stones under corners if needed to level. I'm using red clay soil as the fill dirt, as that's what we have everywhere. It's got lots of minerals in it, but is a poor garden soil, because it compacts too hard around roots, choking off their ability to pick up nitrogen and drowning them when wet because of poor drainage ability. Two wheel barrow loads of fill dirt will provide a remaining depth of about 12". If this is a bit of overkill for you, add another half to whole load. Then you can buy or build less garden soil for the remaining volume. I think about 8 cubic feet (or 200 quarts) of garden soil will fill it the rest of the way, after two wheel barrow loads. Don't worry about fill dirt leaking from the bottom. It will leak only so far before forming sort of a berm that prevents further leakage.
Step 10: "Finished" Garden
Here is a before and after shot of my garden. The after shot shows the raised bed from this project on the left end. I put finished in quotes, because I'll never be finished. There are so many exciting things to do in the future!