Portland cement comes in a powder form that only requires adding water. Unlike similar quick-setting concretes, Portland cement sets much more slowly, which allows you time to mold it to your desired shape. When mixed with organic materials such as peat moss and coconut fibers, it becomes a substance called hypertufa. Hypertufa is an attractive and easy to work with medium for making flower pots and planters for your landscaping. The cured hypertufa lasts for many years and becomes more charming as it ages.
Choose a mold for your flower pot. Use an existing flower pot or cardboard box. Line it with a heavy-duty plastic garbage bag.
Mix 1 part peat moss and 1 part coconut fibers. Combine with 1 part sand and 1 part Portland cement powder. Combine well, breaking up any clumps in the peat or fibers.
Mix in 1 part water, combining thoroughly. Add additional water as needed until the mixture is just moist enough to hold together when squeezed, with only a slight film of water squeezing out.
Place enough hypertufa mixture into the bottom of your mold to make a 2-inch layer. Smooth it with your hands until it is level. Continue adding more mixture and smoothing it up the sides of the mold. Round the rim of the pot slightly with your hands.
Place four ½-inch diameter dowels into the hypertufa on the bottom of the pot to form drainage holes. Leave them in place as the pot dries.
Cover the pot with a plastic bag and set in a 55 F or warmer room to dry for two weeks. Remove the bags, mold and dowels carefully from the pot and let cure for an additional two weeks. Mist it with water once daily during the second curing period so that it hardens without cracking.
Set the pot outside in the rain for for five days or spray it down two or more times a day with water. This allows the alkalinity to leach out of the pot before planting.