Save Your Back: U-shaped Cedar Raised Garden

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Intro: Save Your Back: U-shaped Cedar Raised Garden

I just made a raised vegetable garden for my wife. I used red cedar for the parts that touch the soil to prevent contaminating it with treated wood, which I used only for the bottom. It took me about 40 hours to design and build this; the supplies cost me about 700 USD. I used common hand tools and an electric miter saw. I showed the results to a few friends who requested that I share plans and instructions, so here.

This is my first instructable and English is a second language, so my sincere apologies for any mistakes I made and please feel free to let me know how to improve on all this. Thanks!

Marc

STEP 1: Site Preparation

  1. Cleanup a 11X11’ area in your yard for a 18” clearance around the raised garden
  2. If so desired, cover cleared ground with geotextile and cedar mulch, surround with plastic border.

STEP 2: Base

Cut sixteen 4X4 trapeze-shaped 45° braces with 9” long side

Cut eight 4X4 legs of 16” length

Assemble the eight legs with braces on two adjacent sides; use lots of screws on this.

Cut 2X4 treated wood in the following dimensions; the 45° cuts are made on the 3½” side

  • Three pieces of trapeze-shaped 45° with 94” long side
  • Two pieces of trapezes-shaped 45° with 34” long side
  • One piece of trapeze-shaped 45° with 31” long side
  • Two pieces of parallelogram-shaped 45°, both sides same length: 60”

Assemble and screw the base 2X4's and legs

STEP 3: Frame

Cut pieces of 2X4 treated wood in the following dimensions:

  • 92” : 2 pieces
  • 89” : 2 pieces
  • 59” : 2 pieces
  • 30” : 6 pieces

Cut twenty-four 6” pieces of 2X4 cedar

Assemble the bottom part of the frame as shown in the figure

Cut both plywood pieces using the dimensions shown in the second figure; cut-out openings (dotted lines) for the vertical 6” pieces.

Screw the floor to the bottom frame.

Cut pieces of 2X4 cedar in the same dimensions as for the bottom part of the frame:

  • 92” : 2 pieces
  • 89” : 2 pieces
  • 59” : 2 pieces
  • 30” : 6 pieces

Assemble the top frame (cedar) and join it with the bottom frame.

Turn the frame upside-down; put the upside-down base on top and assemble, then flip the assembly back up. NB : I had to screw a beam between the legs on each side to prevent them from bending/ripping out during the flip.

STEP 4: Walls

Cut 1x5½ cedar boards to the following dimensions:

  • Three boards at 94” (rear)
  • Six boards at 92” (exterior sides)
  • Six boards at 35” (front left and right)
  • Six boards at 58” (interior sides of center alley)
  • Three boards at 26” (end of center alley)

Screw boards to frame.

STEP 5: Weather-proofing (optional)

Insert 6”-high pieces of 1” styrofoam between the bottom and top framing.

Cover earth-exposed cedar with plastic film to slow-down rot.

STEP 6: Floor

Drill ¾” holes every 8 inches or so along whole plywood floor for drainage.

Screw the 1X2 strapping strips every 8” or so.

Screw or staple the mesh to the strapping.

Cover with geotextile and staple in place.

STEP 7: Optional 'gunwale'

This part is optional. I think it looks better with it, plus it keeps the earth in when the wind and rain pounce.

Rip three 1X5½”X8’ cedar boards in half along their length.

Round-out the cuts using a sander or router.

Measure the length at of each top wall board in the center; make the 45° cuts so the length along the center of the gunwale matches the wall board's.

Flatten the rounded top wall board using a sander or plane to ensure a solid gunwale assembly. Screw gunwale pieces centered on walls.

STEP 8: Finish

Fill with earth, plants... I plan to add a drip irrigation system with timer (that's what the piece of black ABS pipe sticking out on the left side is for), but otherwise I'm pleased with the results and so is Nancy!

17 Comments

What is the purpose of the styrofoam?
At the time I built it, I was not sure what my wife would put in it, when we would seed, etc. We have freezing nights from October to May. I have done similar beds in the past where perennials were killed by frost, so the styrofoam here was just a precaution.
very inspirational build good job. Question? I am a little confused on this being soil containment free due to the treated plywood you have used for the bottom of the planter where the soil sits on. My question is, does your design have the treated plywood in contact with the bottom according to your pictures? Or am I not understanding correctly?
thanks for the response as I am ordering lumber as we speak
Hi lordbotabis,
The bottom is treated plywood, with lots of 1" holes for drainage. On top of that, I put some slats/strapping as spacers, a quarter-inch wire mesh and a thick geotextile, so the earth never touches the treated wood as there is an air gap in between. You can see the strapping and mesh on the first photo of step 6, just before I added the last piece of geotextile in the middle. Hope this clarifies things. Good luck with your build!
This is a lovely build...and your instructions and illustrations seem admirably clear...thank you! I'd love to have a couple of similar units in my yard instead of what we currently have! But ours were built with what we had on hand at the time, so maybe eventually we can upgrade!
Thanks! I also always try to reuse the material I have.
can't read the dimensions of the raised garden bed in step 3.
Sorry about that. I guess you have to zoom the image in order to read the dimensions. The cut lengths are also listed below the picture. The leftmost and rightmost pieces are 92" while the horizontal (rear and middle) pieces are 89". All the short pieces are 30".
Nicely done!
What a beautiful and functional build, quite the inspiration!
Bonus: that'll be easy to enclose with a cold-weather frame come winter, and keep right on growing vegetables and fruits. What a gorgeous planter!
I will definitely build a cover for winter; I plan to make it into a steep roof because of the heavy snow up we get up here. But I like your idea; I will make the panels removable so I can put clear plastic sheets on the structure and start gardening earlier.
Excellent build, it looks great so well done.

Barry (ENG)
I've been wanting to make something like this for my parents! Thanks for your insipiring project!
You're quite welcome and thank you for your comment!