Garden Soil vs. Potting Mix

Plants in pots are subjected to more swings in temperature and moisture than plants in the ground. For example, hot weather dries out a pot much faster than it dries out your garden. That’s why the potting mix in a planter has to be very different from the soil in your yard. 

 Garden soil is a combination of clay, silt, and sand with a small amount of organic matter (rotting stuff that used to be alive). This type of soil varies widely from place to place in how fast it drains and how many nutrients it has. Not all plants like all types of garden soil.

Yard soil doesn’t work well in a container because it becomes compacted over time, slowing drainage and reducing air spaces (roots need air too!). To create a more “pot-friendly” growing medium, professionals and homeowners use a soilless “potting mix” that may include peat moss, ground bark, coir, and perlite or vermiculite. This mix is designed to hold some moisture while offering good drainage and air spaces for roots. The large air spaces in the mix help slow temperature changes in the pot, too. However, this type of mix does not have a lot of nutrients. The manufacturer or gardener needs to add a fertilizer to the mix (the bag will say if the manufacturer added fertilizer).