A 5-gallon bucket serves as the outer form for this patio planter; inside is an 8-in. tubular concrete form. If you want to make more than one planter, cut the bucket in half vertically and then tape it together before casting so it will be easy to remove. To create a drainage hole, hot glue or screw a 6-in. piece of 1/2-in. dowel to the center of the bucket bottom.
Prepare a relatively stiff mixture of sand mix or regular concrete. I added a fortifier and polyester strand reinforcement to the mix, but in a warm climate you can get by without them. Dump about 2 in. of concrete into the bucket and bounce it on the ground to settle. Center the tubular form on top of the layer of concrete; then fill up the form, rapping the bucket frequently to release air bubbles. Monitor the tubular form to make sure it stays centered as you work. At the top, strike off excess concrete with a wood scrap.
STEP-BY-STEP INSTRUCTIONS
Step 1: The outer planter mold is a 5-gallon bucket split vertically; the inner mold is a piece of 8-in.-dia. tubular form.
Step 2: Tape the bucket back together securely before filling the planter form.