How to Build Custom Interlocking Planter Boxes

I may keep making a big stink about our gardening efforts this spring, although if you’d take a peek in the backyard you’d probably assume that we don’t do so much as mow the lawn. Taken from the upstairs guest room window, this little lot leaves much to be desired.

In previous years, we lined the garage wall with tomato plants, and shortly after I moved in, I dropped three transplanted trees into my backyard, but these days, especially in the wee beginning of springtime, it looks desolate. Doesn’t help that the dog generally eats in the backyard wearing down patches in the lawn. Oh, and can you tell where the old above ground pool sat thanks to the very sandy soil yielding different color grass? On some days when the grass is longer, I can still see the shadow of a full circle.

Right. To try something new this year, I channeled something I saw on TV and decided to make some planter boxes in which to house my seasonal veggies and assorted flowers. (Get it, the title of this post, boxing? Jabs?)

The interlocking design shown on an episode of Desperate Landscapes on DIY Network was both pretty and a little different, appealing to me because it meant that the exposed edges would be free of bolts and screws holding the assemblage whole. By bolting downwards through the corners, Jason Cameron achieved a clean-lined look, and that, I liked. Real snapshot from the TV on my iPhone for future reference? Sure:

Pete and I brainstormed a little bit recently, deciding that using pieces of 1/2″ x 18″ rebar straight through the wood into the ground might be a less-expensive alternative, and also help to anchor the planters into the ground a little bit. This sweet little artwork was designed on Paper (our newest favorite f-r-e-e iPad app).

Having priced out some of these planter options at a range of places from hardware stores to places like Williams-Sonoma, I knew they could run upwards in price really quickly, especially with a name brand or specific high-quality lumber attached to it. I considered making mine out of cedar to withstand the test of time a little longer than pine, but pricing is always a consideration and for the amount of lumber I decidedly wanted, I still hoped to keep the whole construction under $50. I used a 10% off coupon and saved a whopping $4.92 but it was still just under $50 all-in even without the added savings.

Here’s what I picked up:

• Four 2x8x8′ pine boards ($2.90/each)
• Four 2x4x8′ pine boards ($6.44/each)
• 8 pieces of 1/2″x18″ rebar ($1.57/each)

A few notes:

• I considered going low-rise with just one 2×8 height board, but I worried about the dog overstepping his boundaries. And a dog who oversteps boundaries will be peeing in my tomatoes.
• Two 8″ boards felt a little tall when I stacked them as a visual in Lowe’s. And would have cost me an extra $15.
• One 2×12 board felt thick and heavy and just too monstrous. You know how those boards just look like they’re designed with withstand 10,000 pounds of pressure and will require you to find two extra sets of hands to load them into your Jeep? That’s too much weight for something light and veggie-filled in the backyard.
• The combination of a sturdy 2×8 combined with a lighter 2×4 for accent and a slight rise in wall height felt like the right balance in the end, less heavy than if it were a solid 12″ board.
• And of course if you’re doing this at home, do what’s right for your situation. Not everyone has mammoth dogs to be considering.

I cut the boards in half into 48″ pieces, because to keep things simple, developing a set of 4’x4′ boxes would be easy and efficient. In sets of four (representing each box) I clamped the wood together tightly, and marked off where it would need to be cut on each end to fit in an interlocked pattern. Binding the pieces together just made my cuts happen a little more efficiently than if I were doing singular cuts on the deck with the circular saw.

For the 2×8 boards, I used a speed square to measure and mark the notches at 1-1/2″ x 3-1/2″. That’s exactly the board width x half of the real board height.

When it comes to making these cuts, pay attention to the depth of your circular saw blade. For the shallow cuts, I was able to set the circular saw to 1.5″ deep, but with the deeper cut I was only able to go up to 2.5″ deep.

Which is why I was left to cut through the rest of the way by handsaw and multitool with a cutter attachment. Pete promptly reminded me this morning that we have a sawzall for jobs like this, I forgot, and my triceps are making me pay for it.

My cuts were nowhere near as smooth as what I saw on TV. And that’s why I’m not on TV.

Just to note: In notching both ends of each board, both the 2×8’s and the 2×4’s, I notched on the same side of each board, so the notches when facing upward were all facing the sun, not one side facing the sun and one side facing the ground. Know what I’m trying to say? Probably not. They fit together as a puzzle easily as you’ll see, but an easy puzzle. An ages 3+ puzzle.

Assembling the puzzle was easy enough too. I started by predrilling the holes for the rebar to extend through in each corner, using some cinder blocks as convenient anchors. Using the electric drill gave me a lot of power consistently through all of the boards, and a 5/8″ paddle bit widened a path for the 1/2″ rebar to glide through with not-too-much-and-just-enough friction.

By then hauling them out into the lawn, the 4 sides came together quite easily; once one piece of rebar was in, the structure stayed upright and made configuring the other three corners a snap.

When the planters are positioned, each piece of rebar will receive some clean thwaps to hammer them into the soft ground. When they’re level with the top piece of wood, there’ll be no chance of dog and kid injuries while we play and romp in the backyard.

Stepping back and looking at the set wholly, they’re pretty cool. And bigger than I expected 16-sq.ft. pieces to be. Not as nice as the ones I saw crafted on TV, mostly because I’m no first-rate craftsman, but they’ll be great to house tomatoes and flowers in the backyard this summer.

There’s still more work to be done, mostly digging a bed for them to sit over, bringing in potting soil and fertilizer, and creating a nice little environment in the backyard.