A Simple Raised Bed Design
A Great Plan for Anyone with Beginner Carpentry Skills
By Jeff Merkle – About a year ago, my wife and I moved across the country to acreage in Wisconsin. While we have many plans for the land, our immediate short-term goals were as follows: 1) Convert the existing garden into a chicken run and renovate a chicken coop, 2) Build raised beds close to the back of the house so the whole family can enjoy growing their favorite veggies and herbs. It was my responsibility to come up with a good design for raised beds, and I was told the beds had to keep out the weeds, be easy to use, and resist as many critters as possible.
The simple raised bed design I settled on is perfect for someone like me with an average — at best — level of carpentry skills. Meaning, I have a miter saw that I really enjoy and one of my greatest accomplishments with this tool is that I still have all of my fingers.
Tools I Used:
2″x6″x8′ lumber (6)
2″x4″x8′ lumber (3)
2″x2″x8′ lumber (8)
Chicken Wire, 1 roll, 4’x25’
Chicken Wire, 1 roll 2’x25’
2 ½” Deck Screws
The finished bed will be four feet wide by eight feet long, and stand about a foot high, not including the lid. With the lid, it stands about three feet high. We have found the 4’x8′ footprint to be ideal for managing small varieties of veggies. Also, it plays well to the standard lumber lengths. This year we grew Swiss chard, carrots, green beans, broccoli, and tomatoes (without the lid). If you add the lid, be aware it will limit your ability to grow taller plants.
Find the right site for your raised bed taking into account desired sunlight, water availability, and drainage. The flatter the site the better.
Take two of the 2×6 boards and cut them in half creating four lengths of wood measuring 4’.
With one of the 2×4 boards, make four 11” cuts.
Cut the other 2×4 board into four lengths of 2’
The last 2×4 can be cut into two lengths of 18” with 45° angle cuts on both ends so as to fit a corner.
Take 2 of the 2×2 boards and cut them in half, creating four lengths of wood measuring 4’.
Cut one of the 2x2s into two lengths measuring 21.5″ and one length measuring 45″. This cut can be saved until the end because the lengths may vary slightly depending on the wood being used.
1. Lay two of the whole 2×6 boards flat on the ground, parallel and placed snuggly against each other. Place two of the 11” lengths of 2×4 (corner posts) perpendicular at both ends and secure them with four screws each.
2. Repeat this process with the remaining whole 2×6 boards and 11” 2×4 boards. You now have both of the long sides of the beds.
3. Set the long walls upright and opposite each other with the corner posts facing inward. Connect them by attaching a 4’ 2×6 to the corner posts, beginning with the ground level. Repeat this process with another 4’ length right above the last. You should have two clean corners after this step. The whole bed will be exactly 4’ wide.
4. Repeat step 3 on the other end and your garden bed will be ready.
5. Roll out the 4’ chicken wire in the bottom of the bed and use the aviation snips to cut a rectangle leaving an extra 2″ or so at both ends. Staple the wire into the floor of the bed leaving no gaps. This will keep burrowing critters from sneaking in from below.
6. The lid will be constructed in much the same way as the bed. Lay two of the 8’ lengths of 2×2 on the ground parallel. Connect them at the ends using 2 of the 2’ lengths of 4×4. Duplicate this process to form the other long wall of the lid.
7. These two sides will be connected with two of the 4’ lengths of 2×2 fastened to the lid corner posts.
8. Repeat this step on the other end.
9. You’ll need to add vertical support post in the middle of the long walls to keep the lid from drooping. This can be a piece of 2×2 cut to fit the space and attached with screws. I also recommend another support post running horizontally between the top beams of the lid. This keeps the lid sturdy when it is set on its side.
10. Use the 18’ lengths of 2×4 as corner braces. It can wedge into the corner, one end fastened to the corner post and the other to the lower end beam.
11. Repeat step 10 on the other side.
12. Set the lid on top of the garden bed. It should sit nicely on top with the exact same 4’x8’ dimensions.
13. Line the lid with chicken wire. The 2’ wide wire wraps around the exterior and the 4’ wire covers the top. Fasten it to the frame with staples.
14. If you would like the lid attached to the bed, attach hinges to the side of the lid with corner braces.
1. Wrapping the sides of the lid with 4 mil plastic sheeting works great for growing tomatoes.
2. For better functionality for one person, use chain to connect the lid to the garden box so it will sit perfectly upright when open.
3. Putting down cardboard before you add your soil and amendments helps block weeds and grass. Plus the worms eat it!
Enjoy constructing these raised beds, and I hope you have some “helpers” like I did.
Can you use pressure-treated wood when constructing your raised bed garden?
We reached out to Sally Brown, Research Professor at the College of the Environment – University of Washington, for further information on this subject. Her is her response:
“The old style pressure-treated wood contained chromium, copper, and arsenic. Chromium is a necessary nutrient – but only in the proper form. The oxidized version was the subject of the Erin Brockovich movie. Copper is a necessary nutrient. Arsenic is toxic in the right form and with the right exposure. Newer versions of pressure-treated wood have modified the formula and now a range of materials are used to make the wood resistant to degradation. The critical thing here — and why I don’t lose sleep over people using these materials around their gardens — is the mechanism by which these elements are toxic. To cause harm they have to get from the wood into the person. In soils, these elements are typically not mobile. Soil is high in organic matter that reduces Cr to the nutrient version from the toxic version. Whatever other elements would need to migrate from the soils to the plants being grown and then be taken up by the plants. The person who is gardening would then have to eat enough of these plants to make an impact. That would be very difficult — near impossible to do. Plant uptake for most elements that are not nutrients is minimal and reduced with sufficient fertility. Movement in the soil is limited so only plants growing directly against the wood are likely to see any elevated anything in the soil. In the grand scheme of things to worry about, this is not one. If it is a concern, plant flowers directly against the wood or use a different material instead.”