How to Build a Vegetable Planter to Sit on Cement

Build a round concrete planter quickly and easily using sand and concrete. Lay a trash bag or plastic tarp down on a flat surface. Build a simple plywood box that measures 36 inches square from a sheet of 1/4-inch thick plywood. Hammer nails into the corners of the frame, forming a tight seal between the pieces. Fill the box frame with sand.

Create a hole in the sand that is approximately equal to the size of planter you wish you build. Press a wastebasket or other round container that you want to use as the mold for your concrete planter into the hole in the sand. Press the container firmly with a back-and-forth twisting motion to pack it tightly into the hole. Fill the area around the mold with sand until it is completely compacted. Remove the basket.

Mix concrete, following the directions on the dry concrete mix package. Add dye to the concrete, if desired, to add color or stain to your planter. Pour a 2-inch layer of concrete mix into the bottom of the hole in the sand. Dip a 4-inch dowel in vegetable oil and press it through the concrete into the sand so that the top of the rod is just barely visible above the top edge of the poured concrete.

Use a tube or container that is smaller than the sand hole to form the inside of the planter. Coat the outside of the inner container with vegetable oil. Place the container in the hole so that it rests on top of the dowel rod.

Fill the cavity surrounding the inner container with concrete. Use a tamper to press the concrete into the side firmly while you pour around the form, ensuring a tight, solid construction.

Allow the planter to cure in the sand for three to four days. Remove the inner form and pull the concrete planter out of the sand. Save the sand and frame for future planter projects, if desired.