How to Build a Planter Box Economically
My neighbor came over this weekend while I was outside working, and he asked if he could interrupt my “craft” project. Mind you my miter saw was set up, my tools were scattered about, and I was up on my deck with my impact driver going full speed. He is a nice man…well-meaning…but a craft project?
What was this “craft” project? I was building a cedar planter box, the first of several, to transform my deck into an elevated herb and kitchen garden. My dream is to be able to open my kitchen door and within a few steps snip some fresh herbs and pick some fresh veggies to use immediately in the meal that I am preparing.
When I first moved into my little bungalow the back deck was a bit of a mess. The cover was full of holes, so it leaked like a sieve, the handrail was very rickety, and the deck floor needed to be revived. Oh, and the skirt, well let’s just say it was ugly. Basically it needed a complete makeover.
The deck got its makeover last summer when I had the pergolas and other deck added (more on that adventure here), and I managed to get most of it stained and sealed before Old Man Winter came to visit.
I am very eager to get my kitchen garden going, so I’m building the planter boxes to fit on the deck. These easy-to-build boxes are economically constructed with cedar fence planks and should last a very long time. So let’s get building!
(An apology for the quality of some of the pictures. I built the planter box on the deck that was either is bright sunlight or dappled shade.)
First let’s take a look at the finished product. The beauty of this planter box design is that it can be built to any dimension that you choose with a few simple steps. The planter box I built took full advantage of the materials I used to produce as little waste as possible.
Step 1: Gather your materials and tools.
TIP: When buying lumber for any project…look at each piece that you buy. Make sure each piece is straight and not warped. Also, the fewer the knots the better.
TIP: Use deck screws. They come with a drill bit that fits each screw perfectly without any slipping.
Step 2: Measure and cut the lumber for the basic box.
You will need:
- (8) – 70″ planks for the front and back (long sides)
- (8) – 23″ planks for the ends (short sides)
- (6) – 22″ 2 x 4s
- (2) – 69 1/2″ 2 x 4s (floor supports)
TIP: When measuring your pieces, use your first cut piece as your measuring device. It saves time over pulling a tape for every cut. Do not mark a plank for multiple cuts. Your saw blade takes up space. If you mark a plank for several cuts, your pieces will not be the same length.
TIP: If your saw does not make a clean cut through the width of the plank, simply flip the plank over to complete the cut.
Step 3: Assemble the long sides.
Lay one plank on a 2 x 4 aligning the top edges. The plank should overlap the 2 x 4 by the depth of an end plank. In this way the corners of the basic box will be level and smooth. Attach a 2 x 4 on the other end of the plank. Continue fastening four planks to the 2 x 4s to create one long side. Assemble two long sides.
If you flip over the sides, you should have something that looks like this:
Attach a 2 x 4 piece to the center of each side for a brace. (This is where I made a mistake.)
Step 4: Attach the floor support.
Decide how deep you want the soil to be in your planter box. Then measuring down from the top, attach a floor support to each side. Use 2 1/4″ or 2 1/2″ deck screws. You may need to drill your holes first.
Step 5: Build up the short sides.
Line up the long sides. Starting at the bottom, attach a plank on each end. Build up the ends one plank at a time.
Your planter box should now look like this (except for the center brace):
At this point, you could skip to Step 7 (cut your floor boards) and call it a day. This would reduce the cost of your planter by a little over $33. However, I chose to trim out the corners and top to make a more finished look.
Step 6: Trim out the corners and top.
Measure and cut eight trim boards for the corners. Attach the trim boards with finishing nails.
For a detailed look at the corner trim, this is a birds-eye view of a corner.
Measure and cut trim boards for the top. Miter each corner 45 degrees for a polished finish. Use finish nails to attach the boards.
Step 7: Cut the floor boards.
With the remaining planks, cut floor boards measuring 22 1/2″ long. You will need 13 floor boards, however, the last board will need to be cut in width to fit your box. Using a hand saw or jigsaw, cut the floor boards to fit around the 2 x 4 pieces.
Step 8: Do your happy dance!
You have just completed a very attractive planter box at a fraction of the cost had you purchased it as a kit or fully assembled! You are a financial carpentry genius!
The finished planter:
My planter cost me just at $115.00 excluding tax. I did have a box of the longer (2 1/2″) deck screws that I did not have to buy. I purchased all of my materials at The Home Depot.
What’s next? I will be staining my box with a transparent outdoor stain…probably Thompson’s WaterSeal. This isn’t necessary, however, cedar does turn gray as it weathers and ages. I will be lining my box with a commercial grade landscaping cloth and filling it with good soil in preparation for planting those seedlings I hatched recently (see that post here) and planting more seeds.
Oh, don’t you just love spring!