Gardening Garden Design Garden Projects How to Cast Concrete Planters Create colorful and creative DIY concrete planters for your container garden with these easy (and customizable) step-by-step instructions. By Viveka Neveln Viveka Neveln Instagram Viveka Neveln is the Garden Editor at BHG and a degreed horticulturist with broad gardening expertise earned over 3+ decades of practice and study. She has more than 20 years of experience writing and editing for both print and digital media. Learn about BHG's Editorial Process Published on August 8, 2017 Share Tweet Pin Email Project Overview Working Time: 30 minutes Total Time: 2 days Skill Level: Kid-friendly 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. You don't have to add pigments to the concrete—without it, the planter will be an off-white color. What You'll Need Equipment / Tools 1 Dust mask 1 Waterproof gloves 1 Plastic tub 1 Trowel 1 Vegetable Oil Spray 1 Molds 1 Metal file 1 Sponge brush Materials 1 Cement 1 Quartz sand 1 Perlite 1 Pigment 1 Sealant Instructions Prepare and 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 into the premix. We made three small containers with a batch this size. Add Water Gradually add water to the premix. Blend the dry ingredients and the water with a plastic trowel until the concrete resembles stiff cookie dough and a handful holds its form when squeezed. Wear gloves, especially when using pigments. Spray Molds and Fill Spray vegetable oil on the inside of an outer mold and the outside of an inner mold to facilitate unmolding later. 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. Make 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. Set, Refine, and 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.