Growing Medium is a term used to describe the substance that you use to grow plants in containers. Before I started to educate myself on container gardening I was naive enough to think that all you needed was “dirt” from a neighbors yard or a park to grow plants in containers. I quickly found out that this was not the case. Dirt is an elusive term, so what I am really talking about is Soil from the Ground and the Garden Soil, Top Soil and Potting Soil sold at garden centers and nurseries. Although many gardeners continue to use Potting Soil for container gardens I am finding that most container gardeners who constitently experience success with their containers lean towards using a high quality Potting Mix. So what is the difference? It wasn’t until recently that I realized that there was such a vast difference between Potting Soil and Potting Mix. I decided to ask the sales associate at the garden center which was little help. He informed me that Potting Soil would be just as good as Potting Mix in my containers and could not explain to me the difference between the two. So let’s get down to the bottom of this and try to make some sense out of this obviously confusing subject.
Potting Soil: Contains Soil (Dirt). Potting Soil will often not give optimal results because its thickness does not allow adequate water and airflow in containers.
Best Uses: Raised beds or to fill low or bald spots in your yard
Potting Mix: Contains No Soil (Dirt), sterile mix which may contain a combination of sphagnum moss, perlite and vermiculite. Potting Mix has particles larger than soil to allow the flow of water and air in the container. Potting Mixes drain well while still retaining sufficient water for plants.
Best Uses: Container Plants. Can also be used to start seeds and for root cuttings.
To add to the confusion some Potting Soils do have sphagnum moss, perlite and vermiculite added in. These potting soils may be okay for containers, but I still believe that you will see better results with a Potting Mix. I have used both Potting Soil and Potting Mix in my container garden and I have been more impressed with the results of the health and growth of my plants in Potting Mix. My plants seem to thrive not just survive in this medium. When you are in the garden center and a sales associate claims that it is the same thing remember to look a little deeper. If it contains soil you may be compromising the performance of your containers. Look for a good quality Potting Mix and you will be on your way to healthy, thriving plants.