Difference Between Potting Soil and Potting Mix You Might Not Know
You work to make sure that your garden plants get the best soil possible. And that will reward you with a bountiful harvest. But if you transfer the same soil into a pot and grow your plant on it, you’ll not get the same best result. Do you know why? One possible reason is that you are not aware of the difference between potting soil and potting mix.
Difference Between Potting Soil and Potting Mix?
Many people would interchangeably use potting soil and potting mix. When you buy potting soil at your local nursery, there is a tendency they’ll give you a potting mix.
Technically, potting soil is just dirt that no longer has the necessary elements to support the growth of a plant. A potting mix, on the other hand, does not actually contain soil but a blend of peat moss, perlite, vermiculite, fine barks and others. It is a growing media designed for containers or pots.
Potting Soil, Not Good for Container Plants
The same type of plant requires the same amount of nutrients regardless of its growing media. However, given the restricted area in a pot or container, a healthy garden soil may not be ideal for growing plants in a pot. That is, you cannot just simply get soil in your garden, turn it into potting soil and expect solid growth.
In an artificial growing environment inside the container, potted plants don’t have enough room to spread its roots. With regular watering, an ordinary potting soil would soon compact. The water will then accumulate at the bottom of the pot despite drainage holes. That will cause the plant to drown. Apart from that, potting soil is also limited in essential nutrients that plants needed.
Why Use Potting Mix
A good potting mix is a combination of elements larger than soil particles. That is important in a container to prevent the mix from compacting. It also allows water to drain well and for the air to easily move through it. All these factors are essential for the plants to have a healthy root system.
Good and Bad Potting Mixes
Now that you have already established that you need a potting mix for your plants, the next essential step to do is to identify a good potting mix.
The perfect potting mix is that which holds moisture, fluffy and not too wet or dense. It should not dry out too quickly and will resist compacting. These qualities provide the plant roots with a good balance of moisture, anchorage, air and nutrition.
Potting mixes are now widely available to home gardeners. Remember though that not everything sold in the market is of good quality. Sometimes, a seeming bargain may not be a bargain at all if you are not careful. There are a lot of cheap potting mixes out there that contain dirt and sedge peat which are heavy and easily compact. That is the type of potting soil you should avoid.
Recognizing Quality Potting Mixes
If you are buying a potting mix, it is important to read the label and see if it contains quality ingredients. Some of the essential ingredients you should look for are:
- Aged bark
- Sphagnum peat moss (should not be sedge peat)
Other ingredients that might be present in a potting mix are peat humus, gypsum and compost. If you see products with a label that says “bagged topsoil,” then you should avoid them. While they are usually cheaper, they are ideal only if you are planting in the garden. Also, be careful with products labeled as “Potting Soil.” Although they may also have sphagnum moss, perlite or vermiculite, they usually contain soil that is not the best for potting or container gardening.
Perlite and vermiculite are lightweight volcanic rocks filled with air. Vermiculite is also a valuable component of a potting mix as it prevents the nutrients from leaching away. Peat moss and sphagnum moss, on the other hand, keeps the mix moist.
One good way to test a potting mix is to see how it drains. After placing the soil in your planting container and water it, the water should start to drain in less than 10 seconds. If the water drips very slowly, it is a poor mix.
DIY Potting Mix
You may also want to consider making your potting mix at home. And doing so is actually cheaper than buying.
Here is a good potting mix recipe from The Old Farmer’s Almanac.
- 1 bucket (2-½ gallons) peat moss
- 1 bucket (2-½ gallons) vermiculite or perlite
- A half bucket (1-¼ gallons) screened compost
- 2 cups fine sand
- 2 cups pelleted time-release fertilizer
- ½ cup lime (to counter the acid of peat and keep the pH level near neutral)
This mix is enough to fill two 14-inch tubs. You can double or triple this recipe depending on how much potting mix you need.
For the screened compost, you may also want to try using vermicompost which is also made from organic matter.
Once you have prepared the potting mix, it is important to check its pH level. The ideal pH for most plants is around 7, so you should keep it at that level.
Pot or container gardening is a good option for gardeners with limited space and those that just want some versatility in gardening. Potted plants can be easily moved around as they are not fixed on the soil. That is why this method is also great for growing decorative and indoor plants.
It is important to remember that in using pots, you need a special potting mix for the proper growth of your plants. A potting soil is definitely not a potting mix even though they are commonly used interchangeably.
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