How To Build A Stone Planter

How To Build a Stone Planter Overview

Day-to-day timeline

Friday: Outline the planter Saturday: Excavate and level the base Sunday: Build the walls and fill the planters

Step 1: Know Your Blocks

Using blocks of various lengths allows for a natural-looking, randomized pattern. With only one textured face to work with, you’ll need to cleave certain blocks to get a second face that can be exposed—at corners or anywhere perpendicular walls meet. To do so, set a wide mason’s chisel on the score line and strike it with a maul to split the block. Clean off any jagged chunks with the claw of your brick hammer. Our blocks have tabs that can be knocked off to create the necessary wedge shape for convex walls.

Step 2: Lay Out the Planter

Cleave an end from four blocks and position them at the corners of your rough outline. Place blocks of varying sizes between them, keeping the sides parallel. Divide the interior area with two walls that create equal-size planters; every other course will overlap the main walls, so just make sure you won’t be left with gaps between blocks. If so, you’ll need to adjust your planter’s width. Once the layout is complete, mark the outline with a spade.

Step 3: Dig the Base

Excavate the area. Starting at the low point of any slope, use a spade to excavate past the loamy topsoil—6 inches or so, depending on your locale.

Step 5: Set Level Lines

Once the area is roughly excavated, set up a grid of level lines so that you can check your depth. Drive stakes near each corner and every 2 feet along the sides. Beginning at the uphill end, stretch the line between two stakes about 4 inches off the ground and level it using a line level. Instead of tying the line in place, notch each stake so that you can easily unhook it while leveling the base. Work your way around the perimeter line, leveling as you go, then add level lines stretching side to side to create the grid. Measure from the level lines to the base of the excavated area. Dig or fill as necessary until the entire base is level and equidistant from the lines.

Step 5: Add the Paver Base

To create a stable, well-draining base for the structure, lay 3 inches of paver base (¾-inch crushed stone and dust) into the excavated area.

Step 6: Tamp and Level the Base

Using a tamper, compact the base. Check the distance from the base to the mason lines frequently to keep the bed level. Add layers of paver base and tamp each one until your depth is equal to half that of one block, plus 1 inch, at the ground level’s lowest point.

Step 7: Lay the Leveling Sand

To simplify fine-tuning the height of the blocks, add a 1-inch layer of leveling sand. Distribute it evenly with a steel rake. The bed should end up half the depth of one block at the ground level’s lowest point.

Step 8: Lay the First Course

Place the first block on the foundation at the highest point of ground level. Use a rubber mallet to set the block in the sand. Use a level to check it side to side, front to back, and corner to corner. Hold the next block beside the first and drop it in place to avoid dragging the sand between blocks. Level and set the block, and place a level across both blocks to check them. Run your hand across the joint and use the level as a straightedge to make sure the tops of the blocks are flush. Set the remaining blocks in the same way, taking care to orient the textured faces outward along the perimeter. For the interior walls, the textured faces should be oriented toward the short end of the planter.

Step 9: Stack the Courses

To create a dry-stacked look and give the structure strength, stagger the joints on each course. On every other course, lay beads of masonry construction adhesive with a caulk gun, and “tie in” the interior walls to the perimeter by overlapping their end blocks with the main walls. Keep building up until each tier is three courses from completion, including the cap layer.

Step 10: Fill the Planters

To keep the planters from holding water—and freezing and cracking—fill each one almost to the top with drainage stone. This also strengthens the structure.

Step 11: Prep the Planters

To contain the soil, lay landscaping fabric over each planter, as shown. Use scissors to trim it just shy of the face of the walls; it will be sandwiched beneath the next course. If you build around a lamppost, like we did, snip a hole in the fabric big enough to fit over the lamp.

Step 12: Lay the Final Courses

Layer the final two courses on top of the landscaping fabric, then add the cap blocks, finish-side up. Scribe and cut them to fit as needed. (For custom cuts, create your own score line by chiseling a V-shaped channel all the way around the block.) Top off the planters with potting soil, and plant your favorite blooms.