Planter Box - Free Woodworking Plans

Before we can finish, we need to install a drain. After a lot of thought, we settled on a conduit drain (using electrical parts, ironically) that shouldn't leak water through the plastic into the box.

Cut a 6" piece of 1/2" threaded PVC conduit into a 3" piece. Then, glue the threaded piece into an electrical lampholder cover, but thread it through the back side of the cover (rather than from the front).

Drill a 7/8" hole through the side of the plywood box at the height that you'd like the drain. Cut the same diameter hole through the 6-mil plastic.

The lampholder should include a rubber gasket, but we're not going to rely on this gasket alone. Apply a healthy bead of silicone caulk around the perimeter on both sides of the gasket, then push the conduit through the hole in the center of the gasket and finally through the hole in the plastic liner and plywood box. Screw the lampholder into place with short wood screws.

On the outside of the box, you may now want to glue a 90-degree elbow to the conduit facing downward. A couple of coats of paint will help camouflage the drain.

Finally, we'll need to place some trim around the top-inside edge of the planter box to cover the staples that hold the liner in place. Cut and carefully tack some 45-degree mitered 1-3/4" wide trim boards around the inside edge (much like you tacked the trim around the outside edge in a previous step). Fill any nail or screw holes and paint (or stain and polyurethane) these trim pieces.

TIP: It is a good idea to paint or stain these trim pieces before you cut and install them. They'll need a bit of touch-up after installation, but it is much easier to paint before installation than after.

When using the planter, place couple of inches of 1-2" rocks in the bottom of the planter, then put your dirt on top of the rocks to help with drainage.