Lots of products are made of granite, clay or concrete. Granite is beautiful and makes stunning counter-tops. Clay is natural and potters can throw it into all kinds of useful or decorative items. Concrete is extremely versatile and is used in building, paving and other industrial or urban applications.
Stone weighs around ten times as much as our Linear Low Density Polyethylene resin. A large concrete planter pot could weigh around 600 pounds or more, that’s a huge shipping cost!
A heavy item made of stone would also require a lot more packaging before it is shipped along with any additional transportation fees.
Concrete and stone are porous, meaning water can seep through the surface and stain, damaging the product. It can also suffer water leaching in which concrete leaks moisture, causing bacteria, mold and fungus to grow.
Granite can be sealed against moisture, but would need regular maintenance. Stone products can also only be sealed inside OR outside to prevent trapping moisture. This shows that the porous nature of stone isn’t ideal for growing plants in.
Planters are meant to hold soil and plants. Unfortunately, concrete cannot contract and expand in the winter when soil freezes and thaws. This can cause your stone planter to crack or break.
Even during the summer, tree roots will grow up from the soil into concrete sidewalks and split or break the concrete slabs because cement cannot bend.
Concrete can also be damaged by corrosion, since it contains aluminum and is often reinforced with steel or other metals.