How To Make A DIY Concrete Block Planter Box | Hometalk
The pea gravel was used to fill in the air gaps between all this and give the soil a flat surface on top –see Step 4 for reference. How To Make A DIY Concrete Block Planter Box Step By Step. Step 1. Wash The Concrete Blocks. Use a power washer to wash the blocks, and add TSP to the soap container in the washer.