How can I create DIY large concrete planters for my garden?

To create DIY large concrete planters for your garden, you will need a mold, concrete mix, water, a mixing container, a trowel, and a release agent. First, prepare the mold by applying the release agent. Mix the concrete with water according to the instructions and pour it into the mold. Use the trowel to smooth the surface and remove any air bubbles. Allow the concrete to cure for at least 24 hours before removing it from the mold. Finally, place your new concrete planter in your garden and enjoy!