We designed this outdoor planter with traditional and classic detailing in mind. It would be a great addition for your porch, deck, or patio.
Cape Cod Style Planter Box
We call this planter box the “Cape Cod” because it reflects the architectural style of the north east sea coast. Our aim was to give it classic styling, but with a casual appeal. The traditional features will work well with many traditional house styles and can create a finishing touch to a special place in the yard or in an area that you would like to highlight, such as using it as an entry feature at your front door.
This planter box will hold up to a 14 inch diameter clay pot, or other container.
The following are the materials you will need to build this DIY outdoor planter box.
4 – 2 x 2 Posts, each cut to 15 1/4” length; we used cedar for it’s insect and decay resistant properties
16 – 1/4” x 4” Slats, each cut to 10 1/2” length
4 – 1 x 2 Top Rails: (there are 2 different lengths)
- 2 – cut to 17 5/8” length
- 2 – cut to 19 1/8” length
4 – 1 x 4 Lower Rails: (there are 2 different lengths)
- 2 – cut to 17 5/8” length
- 2 – cut to 19 1/8” length
2 – 1 x 2 Cleats, each cut to 14 5/8” length
2 – 1 x 4 Floor Planks, each cut to 17 5/8” length
4 – 1 x 3 Cap with mitered corners (45 degrees), each cut to 19 5/8” length (it’s outer length)
24 – 1/2” Wood Buttons
38 – 8 x 1 1/4” Stainless Steel exterior wood screws
64 – 3/4” x 17 Stainless steel exterior wire nails
14 – 1” x 1/2” Hot-Dipped Galvanized or Stainless Steel L-corner braces with screws
How to Make It
After all the pieces of wood have been cut, it is important to put a high quality exterior grade primer (if you will be painting it), or a coat of high quality exterior grade stain primer (if you will be staining it) on the entire surface (including the ends) of each board before you begin to assemble the planter box. This will reduce the chance of any bare wood from becoming damaged or rotting due to water exposure. Water will find its way into every nook and cranny.
As you assemble the planter box, use a quick square to help get all the boards square to one another. If you do not keep everything square as you are connecting the pieces together, you’ll likely get lopsided results!
Also, to help create a solid and stable box, be sure to use the recommended screws, not nails, for joining the structural pieces. Overtime, nails have a tendency to pull out of wood. Two great features of using stainless steel screws are: they are rust resistant and are designed with a self-drilling tip, and a head that will countersink itself flush into the board.
On this planter box, the screws that will connect the 4 top rails and 4 lower rails will be covered with 1/2 inch round wood buttons. See below sketch for the locations for these screws and the wood buttons on the rails.
The screws in the shorter rails (17 5/8” length) will have a different location than the screws in the longer rails (19 1/8” length). Drill the countersink openings for the wood buttons with a 1/2 inch flat wood paddle bit. Drill only deep enough to accommodate the peg of the button. Prime the inside of the countersink opening.
Begin to build the planter box by framing the two sides with the shorter length (17 5/8 inch) rails first. These two identical sides are opposite to each other. Start by building one side completely, then the other side. Attach the 1 x 4 lower rail to the 2 x 2 posts with the screws. Position the rail so that the bottom edge of the rail is 2 inches from the bottom of the posts. Next attach the 1 x 2 top rail to the posts. The top edge of the rail should be flush with the top of the posts.
Next attach the 1 x 2 cleat (wider dimension perpendicular to the rail) to the inside of the lower rail with 3 of the braces. The bottom edge of the cleat should be 1 1/8” up from the bottom edge of the lower rail. Attach the braces underneath the cleat, locating one of the braces centered on the cleat and the other two 1 1/2” from each end of the cleat. The cleats will support the 1 x 4 floor planks.
To complete this side of the planter box, attach 4 of the 1/4″ slats. Pre-drill holes in the slats only, so they do not split when nailed to the rails. The pre-drilled holes (2 at the top and 2 at the bottom) for each slat should be 1/2″ from the ends of the slat and 3/4″ in from the side edges. Position the slats so that there is a 1/8” gap on each side of the slat. Nail the slats to the top and lower rails with the upper end of the slat flush with the top edge of the top rail.
Repeat the same steps to make the opposite side of the planter box.
With the first two sides framed, connect them by attaching the 1 x 4 floor planks to the two cleats. Center the planks on the cleats leaving a 1 3/4” inch space between them. Use two screws at the end of each plank.
The last two sides will use the longer rails (19 1/8 inch). On the third side, attach the lower rail to the two posts, then the top rail. Align the rails with the rails on the adjacent sides. The rails on the third and fourth sides, being longer, will overlap the ends of the rails on their adjacent sides. Attach the slats the same as the other sides. Build the last side the same as the third side.
The final step is to attach the 1 x 3 boards for the cap. The corners of the cap are mitered at 45 degrees. The longest edge of the mitered cap board should be 19 5/8 inches. The cap boards cover the post tops and have a 1/4 inch overhang on their outside edge. Attach the remaining 8 braces to the posts first before attaching the caps. See below photo for attaching braces.
Finally, use wood glue to attach the wood buttons into the countersink openings. Use all purpose caulk to seal around the buttons (make sure any caulk you is paintable or stainable, depending on the finish you have chosen). Finish up by giving the planter box the final coat of exterior grade paint or stain.
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