Because the terms are often used interchangeably, people often believe that they’re the same thing. There are, however, a few key differences and similarities that are worth mentioning so read on to learn more.
Before we get too far along, it's important to note that whenever the word “potting” is included in the title of a soil, we're talking about soil that is NOT intended for use when planting in the ground. Instead, it's intended to be used in a container when a gardener must provide proper drainage: in, say, a ceramic pot or a gardening bed, a pre-built area for the garden, and so forth.
Comparison Between Potting Soil vs. Potting Mix
Okay, we've clarified that we use both “potting soil” and “potting mix” when we’re talking about planting in a container. If that’s what you’re doing, then we generally default to recommending “potting soil.” Both potting soil and potting mix provide the same primary benefit when you plant in a container and that’s drainage. Drainage is always a concern in container gardening because most plants don't do well when they constantly have "wet feet." Plant roots require oxygen and potting soils/mixes both have good pore space, which provides more oxygen. Now, here is where they start to differ…
Besides the fact that the two potting products have different ingredients, there are additional differences.
Potting Soil
- Potting soil is a structured soil (man-made), it doesn’t have any actual soil in the compound. It’s formulated to provide optimum drainage which is critical when you’re planting in any sort of container (pots, elevated gardens, etc).
- Potting soil provides the basic needs of any plant; it’s a growing medium that will support the plant and provide space for roots to grow well.
- Because potting soil doesn’t contain organic material, you’ll need to incorporate a fertilizing practice into your plant care. The type of fertilizer required will differ by the kind of plant you’re growing.
- Potting soil may include a low ratio of organic fertilizer. The Espoma brand of soils also include mycorrhizal spores that work with a plant’s root system to increase the efficacy and size of a root system.
- Potting soil is perfect for growing flowers, succulents, and houseplants. Some gardeners use it in very large containers because it’s significantly lighter in weight.
Potting Mix
- Potting mixes have been developed because container gardening has grown in popularity. As our homes and outdoor living areas become smaller, we try to maximize the limited space.
- Potting mixes are essentially potting soil with organic matter added. Most often they will have a low-ratio fertilizer and may also include bio-stimulants like mycorrhizal spores.
- Despite the (pretty confusing) similarity to the name “potting soil,” it does not contain any soil. Instead, this mix contains organic substances that help with drainage: peat moss, sphagnum moss, pine bark, and so on. Additional organic material also provides the nutrients that plants need for optimal health and these differences are primarily what make up the higher cost.
- Potting mixes were primarily developed to assist with vegetables and crops being grown in containers. Many cannabis growers also use potting mixes as it tends to yield the best results.
So, the real question may be, which one is better?
When to Use Potting Soil vs. Potting Mix
When making a choice for your potted plants, it really just comes down to one question. Are you growing edible plants — such as fruits, vegetables or herbs? If so, your best bet is going to be to use a potting mix. This will provide you with the best performance and highest crop yield. If you happen to be growing cannabis, potting mix is also your best option and we have a special mixture called “Happy Frog” that comes highly recommended.
Alternatively, if you're not growing plants that you intend to eat — perhaps we're just talking about annual hanging baskets, houseplants or succulents — then potting soil is going to be your better choice. It's generally a more cost-effective option and is sufficient for those needs. Just remember that you may need to supplement the potting soil with a fertilizer regimen.
Learn more: How to Pot and Repot Your Indoor Plants: Advice From the Professionals
Balancing Your Soil
Many to most garden plants grow best in loam, which contains an ideal balance of 40 percent sand, 40 percent silt, and 20 percent clay. Balancing your soil, then, means understanding the soil’s current composition and then fine tuning it to meet the optimal needs of your plants—recognizing that not all plants flourish in the typical composition.
Fortunately, we offer a wide range of today’s best products, which are more specialized than they once were—allowing you to more granularly meet precise requirements to grow your plants. Options include organic potting soil, as well, which contains natural ingredients instead of pesticides or other chemicals. It may include processed minerals to help with the soil’s drainage and aeration.
Talk to the experts at Decker’s Nursery for more specifics by stopping in during our retail garden center’s open hours. You can ask questions online or by phone at (631) 261-1148.
The History of Potting Mix Development
Back in the 1950s (and earlier), people got their own soil, often from a wooded area that included leaf bits and twigs to provide a natural compost. They’d shovel some into a bucket, Garden Culture Magazine shares, with the soil likely lasting for just one season. So, people would return to their special spot to get their next bucket full of soil.
Greenhouses made their own potting soil although there were no standards. In that era, nurseries didn’t sell many container plants, and the quality of potting material was inconsistent.
In the 1960s, Cornell University horticulturalists developed the Cornell Peat-Lite Mix, which was more commonly known as the Cornell Mix. This was the first potting mix, a blend that contained sphagnum peat moss, allowed air to flow around plant roots, drained well, and contained no seeds for weeds. Plus, it was light enough for someone to carry the material easily enough. They developed multiple variations, too, according to grower preferences and crops grown.
Since then, potting mixes have been further refined with plenty of specializations created.
Choosing the Best Potting Mix
When seeking the right potting mix for your indoor and outdoor container plants, Espoma Organic Potting Mix for All Potted Plants is ideal for most houseplants. This mix is a rich blend of sphagnum peat moss, humus, and perlite—and then enhanced with Myco-tone®. Containing only the finest natural ingredients, this organic potting mix is fortified with the following: earthworm castings, kelp meal, alfalfa meal, and shrimp meal. It does not contain any synthetic plant foods or chemicals.
Choose Decker’s Nursery
Here at Decker’s Nursery, we are a family owned and operated retail garden center with everything you need to either create a beautiful garden full of lush plants or grow healthy houseplants—all at reasonable prices. We invite you to stop by anytime during our open hours or you can contact us online. We’re experienced and passionate about plants, and we’d love to help you!