Want to add interest to your container garden? Try making your own concrete planters! Disposable containers, such as small milk cartons and 4- to 6-inch nursery pots, work well as outer molds for pots; reusable plastic tumblers from the dollar store prove fitting as inner molds. Flexible plastic molds work best. Rinse molds and tools thoroughly so they can be reused.
Estimate the amount of premix needed for a few pots by filling the molds with dry premix, then pouring it into a plastic tub for mixing. We prepared a batch of concrete and pink concrete pigment (either Tea Rose, Blush, or Morning Mist by Direct Colors) to make several pots at a time in each color. Keep reading for more detailed instructions of this innovative project!
What You Need
- Dust mask
- Quartz sand
- Plastic tub and trowel
- Vegetable oil spray
- Metal file
- Sponge brush
Step 1: Prepare & Mix
Gather materials and work outdoors, wearing a dust mask and waterproof gloves. Make white-base concrete premix with equal parts of white portland cement, quartz sand, and perlite (available at building suppliers).
Using each mold as a measure, scoop dry mix into a tub and add 2 teaspoons of concrete pigment of your choice (available at directcolors.com) into the premix. (We made three small containers with a batch this size.)
Step 2: Spray
Spray vegetable oil on the inside of an outer mold and the outside of an inner mold to facilitate unmolding later.
Step 3: Add Water
Gradually add water to the premix (above), blending with a plastic trowel until the concrete resembles stiff cookie dough and a handful holds its form when squeezed (below).
Step 4: Place in Mold
Fill a well-oiled outer mold with concrete to within 1–2 inches of the rim. Press an oiled inner mold into the concrete until a pot with at least 3/4-inch-thick walls forms. Level the top of the molded concrete.
Step 5: Create Drainage Hole
While the concrete sets, push down on the inner mold and twist it back and forth every 30 minutes. When the concrete has set enough to hold its form, remove the inner mold, and make a drainage hole in the bottom of the pot.
Step 6: Set, Refine, & Seal
Allow the concrete to set for 24 hours; remove the outer mold. Let the cast concrete set for another 24 hours. Refine edges with a metal file. Brush concrete sealant on the outside and inside of the pot and let it dry; repeat.