$23 DIY Cedar Planter Box

2 Materials
3 Hours
This is an inexpensive yet outdoor-ready cedar planter box that can hold about 3 full bags of potting soil and has about 3 square feet of surface area.
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For this project, all you need as far as lumber is 9 pickets measuring 5/8" x 5 1/2" x 6' and a single 2x4 (8 ft long). You'll also need some brads and a brad nailer or, optionally, just outdoor screws such as decking screws.    
Start by ripping the 2x4 in half length-wise. This can be done with a table saw or a circular saw.
Cut all of the 2x2 pieces needed for the project. Cut the following from the 2x2s:
  • 36” (2)
  • 13” (2)
  • 10” (4)
  • 6" (4)
Put the base together by predrilling the holes and using 3-inch screws as shown in the video. Assemble the two 36" pieces with the 13" pieces between them to form a rectangle.
Cut each of the full pickets at this point. Here's the list:
  • 36” (6) - Long siding
  • 17 1/4” (6) - Short siding
  • 16 1/4” (6) - Floor board
With the floor boards cut (the 16 1/4" pieces), attach them to the 2x2 base using 1 1/2" screws. Be sure to predrill the holes, like you see in the video, to avoid splitting the pickets. There should be enough room between the boards for a bit of space. This will provide drainage for the soil.
Next attach the 10" pieces to the corners to create the inner frame. Predrill through the bottom and use the 3" screws to attach each piece.
With the inner frame assembled, you can now attach all of the pickets. Place each of your 36" pieces, starting with the first row being attached to the base. The first row should sit below the base and you can move up from there - this will leave room for the feet. If this is unclear, just check out the video where you can see this in action.

When the long pieces are on, finish up by putting the shorter end pieces on (the 17 1/4" pieces). I used a brad nailer for this but if you don't have one, screws can be used as well.
Add the feet using brads for now.
Next, cut your corner pieces. For this part, you have two options. The easier option is to just cut a picket in half lengthwise and leave square corners. The downside is that you'll have some of the cut sections exposed, which won't look as good as if you use the second method.

The second method involves using a 45 degree cut to hide the exposed edges. It's a tiny bit more work but looks way better. Check out the video to see how this is done.
Whichever method you choose, you'll need to cut the boards to length at this point. You should end up with 8 corner pieces at 18" tall each.
Add your corner pieces using exterior wood screws. If possible, use screws that are 2" in length. I used the 3" screws and they stuck out just a bit.
For the top frame, rip your last picket in half lengthwise.
For the top frame, rip your last picket in half lengthwise. Get the measurement for your width and length just to be safe. You'll want to make the outside measurement for your top frame at least as wide and long as your existing box.
Assemble the top frame with brads and then attach it to your box with brads as well as two screws per side. At this point, I recommend sealing the entire box with water seal - especially the 2x4 pieces. The cedar is a naturally rot and mildew resistant material but it certainly wouldn't do any harm to seal it as well. Also consider adding weed barrier to the inside of the box with some holes poked in the bottom for drainage.
And that's it! Each box holds about three large bags of potting soil and this project can be used for flowers, fruits or vegetables. If you plan on using this for vegetables, however, be sure to use toxin-free finishes and avoid using chemically treated or pressure treated lumber.

Suggested materials:

  • 2x4   (Home Depot)
  • Cedar Fence Posts   (Home Depot)

Frequently asked questions

Have a question about this project?

  4 questions
  • Anneliese Clear Anneliese Clear on Jul 24, 2017
    You mention that the cedar is naturally rot resistant, however a "standard" 2×4 is not. Did you use an outdoor deck/pressure treated 2x4? If not, how will you prevent the interior support posts from rotting away in a couple of years?

    • LRN2DIY LRN2DIY on Jul 24, 2017
      Great question - we sealed the entire thing with water seal before putting in the weed barrier. I'll update the post to reflect that. I mentioned it in the video but forgot to in this write-up.

    • Anneliese Clear Anneliese Clear on Jul 24, 2017
      Thanks for the quick reply!

    • Jewellmartin Jewellmartin on Jul 28, 2017
      After the water sealing and weed barrier, I would be pleased to get four years out of this box. Best wishes 😇

  • A A on Jul 28, 2017
    I like the project, but out of curiosity, was there a reason you opted not to buy pressure treated lumber? Also, why rip 2 x 4s, why not buy 2 x 2s? The cost difference is not significant. We have ripped 2 x 4s before because they were on hand, but I've noticed that there is a slight size difference between a 2 x 2 board and a ripped 2 x 4 (of course neither are actually 2" x 2" or 2" x 4"). Also, if the 2 x 4 has any warp, you won't get true to size 2 x 2s along the length of the board.

    • Lac8091757 Lac8091757 on Jul 28, 2017
      Pressure-treated lumber has chemicals that can leach into the soil and cause damage to the plant. If this were used for food 'crop' or herbs, the pressure-treated wood would contaminate the food. Cedar is safe for most plants.

    • LRN2DIY LRN2DIY on Jul 28, 2017
      Those are all great options. I honestly used non-pressure treated 2x4s because I had plenty of them around and I had water sealer as well but using pressure treated 2x4s makes more sense as a starting point. As for 2x2's vs 2x4's, I found that, at least in my area, 2x2's are harder to come by. The local Home Depot doesn't stock them. In the end, like most DIY projects, you work with what you have, which is what I did here.

    • A A on Jul 28, 2017
      Lacey: I've used PT lumber for years in raised veggie beds with no ill effect. After 2003 the industry stopped using CCA to treat the lumber. If you want more info check out this website: http://www.naturalhandyman.com/iip/infxtra/infptforraisedgardens.html

      LRN2DIY: Thanks for you're response and I am definitely all about using up what I have on hand. Also, I've not had trouble finding PT or non PT 2x2s in my area. Good work and it looks great!

    • Lac8091757 Lac8091757 on Jul 28, 2017
      Thanks, Artemis. I have some scrap lumber from having a fence/deck/pergola built and may try building a couple raised beds from that. I love this technique and am anxious to give it a try :)

    • A A on Jul 28, 2017
      Good luck on your raised beds.

    • Ardale Ardale on Jul 29, 2017
      I for one would use the cedar instead of the pressure treated wood! I think you could also use those plastic decking boards if you want something that will hold up longer then you do but you'll eventually have to paint it since it fades over time. I just happen to think the cedar looks prettier then that green tinted pressure treated wood and I know they no longer use creosote to treat pressure treated wood because it's been known to cause cancer the new pressure treated wood uses arsenic hence why ants flock to the new pressure treated woods like crazy. I would never use pressure treated wood in raised beds I plan to plant food crops in. Just because you'd done it and eaten crops grown in it doesn't mean you won't develop cancer somewhere down the road so I say better safe then sorry!

    • A A on Jul 29, 2017
      According to the article, arsenic is no longer used (that's the A in CCA) and creosote is still used but only in lumber for telephone poles, bridges, etc. industrial applications. Creosote treated lumber is much darker and pretty easy to spot and you should stay away from it.

      I stain my PT planters after I build them so the color is at my whim. Everyone has there own style, so use which ever you prefer. Some cedars are on the endangered list and cypress is particularly endangered. That's why I don't use cypress mulch.

  • JoLeen Bolton JoLeen Bolton on Jul 28, 2017
    I thought weed barrier blocks weeds, but allows water through, so you wouldn't need to poke holes in it, would you? Love your planter, it's just what I need in my front yard!

    • LRN2DIY LRN2DIY on Jul 30, 2017
      My understanding is that it should let water through but by poking holes in it, there's no question, and it would also let water through faster. Probably not a big deal if you don't cut holes in it.

    • Patti Sleightholm Patti Sleightholm on Aug 10, 2017
      I believe it's the bottom of the planter that you poke holes in for drainage. The weed barrier on the inside bottom is to allow water to drain through the holes but prevent losing the soil through the drainage holes.

  • Phi28505863 Phi28505863 on Jul 29, 2017
    Please describe the water sealer" and tell me where to get it.

    • Kim Kim on Jul 31, 2017
      Thompson's Water Seal available at any hardware store or lumber store, such as Home Depot, Menards, Ace Hardware, etc.

    • Angela johnson Angela johnson on Jul 31, 2017
      I'd read the reviews for Thompsons Water Seal before deciding to use it. (:

    • Ski21742414 Ski21742414 on Aug 10, 2017
      I have thought about using linseed oil (not boiled) which is just really flaxseed oil because I don't want to use chemicals...want to grow lettuce in mine.


Join the conversation

2 of 22 comments
  • Danielle Odin Danielle Odin on Jul 29, 2017
    It is much cheaper than the bought one but if a person doesn't have the table saw and all the other tools needed I will be more expensive. When I had all that equipment, it was easy for me to make stuff. But today living in an apartment I would have to buy the ready made.

  • DiAnn DiAnn on Jul 30, 2017
    This planter box is beautiful. Thank you for sharing.