Last Updated on July 21, 2020
Most gardening experts know which potting soil to choose for what plants, through years of experience in the garden as a profession or a hobby.
They can pick out the best potting soils, and even make their own potting mix, according to the needs of the specific plant. They make it look so easy and effortless, but to a beginner gardener or a layman, it might not be as easy as that.
If you are thinking of turning to gardening or educating yourself on the subject, one of the most important topics that will come up is that of potting soils and which ones to use.
While supermarkets now have a variety of different potting mixes to choose from, you still have to know what soil would be best for your plant.
Table of Contents
- What is Potting soil?
- Difference between potting soil and Gardening Soil
- Components of Potting Soil
- What are the different types of potting soils?
- Choosing the best potting soil
What is Potting soil?
Potting soil, technically, is not soil at all. It is a mix or a blend of different materials, such as sphagnum moss, perlite, bark, compost, vermiculite, or coir, that feed the plant.
The soil-less mixture is preferred because soil attracts many kinds of fungi and pathogens that can be the death of the plant. The different components of the soil also ensure better draining, higher nutrients, and even fertilizers in the mix.
Potting soil is expensive and is primarily deemed best for indoor and outdoor plants kept in pots, planters, and containers.
Difference between potting soil and Gardening Soil
As a newbie to gardening, it is understandable if your first question still is, “What is the difference between potting soil and gardening soil?”
Many of us initially had the same question. Why is the soil that is used to grow plants in the ground not good enough to be used plants in a planter or container?
The plants, in gardening soil, would be devoid of the necessary nutrients, water drainage, and conditions that are essential for the plant to grow.
Potting soil is filled to the brim with all the nutrients a plant needs.
It also helps drain and distribute the water evenly for the plant to take up, where else gardening soil clumps together and retains the water, killing off sensitive plants. Potting soil’s superior ability to drain is the main reason it is used for most indoor plants.
Gardening soil also contains various bugs and fungus, which are lethal to a plant. The potting ‘soil’ is soil-less, and thus, does not house these terrible pests.
However, potting soil is pricey, and making a large dumping ground in your gardens a bit uneconomical. Keep them exclusively for your container plants because drainage is trickier in containers and pots. Plants in your garden don’t face the same issue and can grow with gardening soil just fine.
Components of Potting Soil
As mentioned above, potting soil is a mixture of different ingredients. The ingredients and their proportions determine how healthy it will be for the plant.
This is the most abundantly used ingredient in any potting soil. Peat moss is the remaining decayed matter of the sphagnum moss that has died in bogs and remained for thousands of years. It is harvested from peatlands.
The partially decomposed material is ideal for either holding in more moisture in plants or breaking clumps to improve better draining. It is also lightweight and inexpensive. That is why peat moss or sphagnum moss is such a popular ingredient in any potting soil.
Pine bark in itself doesn’t do much for the plant as it has no nutrients to give; however, when combined with peat moss, it can be transformational, as it helps create more air space for the plants and also helps with retaining water and fertilizer.
It is acquired from paper mills and mixed into the potting mixture.
The tiny white shards in the potting soil are another important component of the potting soil.
It is called perlite, and it is actually heated volcanic glass. It is mixed into the potting soil to ensure that the soil does not get too dense and heavy, making it easier for the water to drain through the soil.
Vermiculite is also a volcanic material, and serves, more or less, the same purpose as perlite, i.e., to create more air spaces in the sand and improve circulation.
However, vermiculite is slightly different than perlite because it also helps hold a little moisture and also fertilizer, ensuring that the fertilizer and other nutrients are not simply washed away, but remain in the proximity of the roots for a while.
Coir Fiber is the by-product of the coconut industry and serves the same purpose as the peat moss, except that it is more expensive and more environmentally friendly.
Pulverized limestone is also added to the mix, especially to neutralize the pH level of the peat moss. It is also relatively inexpensive and easy to find.
Sand is added to the potting soil to give it some weight. It is also very good for drainage and is abundantly used in mixes specifically for cacti.
What are the different types of potting soils?
All Purpose Potting Soil
This potting soil is best for most indoor and outdoor plants growing in containers.
It is a general mix of ingredients, made with no specific plant family in mind. All-purpose potting soil is the best bet if you want to buy a potting soil but don’t have much knowledge about which ones to buy.
Organic Potting Soil
Organic mix is made from natural, plant, and animal-based materials, such as worm castings, food compost, manure, bones, and remains of decayed plant and animal matter over the years. The organic material is incredibly fertile.
Seed Starting Mix
This is a very fine mixture of potting soil and provides the ideal conditions for germinating. It is low in nutrients, making the plant’s roots to branch out to look for food and nutrients, helping them grow and expand quickly.
Orchid Potting Soil
Orchids require good air circulation more than anything else and also need well-drained soil that prevents the roots from staying wet. This mix is formulated specifically to help those sensitive orchids grow.
Cacti and Citrus Potting Soil
Cacti and citrus plants also need good drainage, and thus in these specific mixtures, sand is added to aid the draining.
Moisture Control Potting Soil
These mixes contain moisture-controlling pellets, which do not let the soil dry out entirely, letting the plant take up moisture as it needs.
Outdoor Potting Mix
These are made for container plants indoors and outdoors, and give the same environment for growth that these plants would have gotten growing in the forest. They usually contain more fertilizer and moisture-retaining pellets.
Choosing the best potting soil
Now when you have to choose the ideal potting soil for your plants, you will be better equipped with the necessary knowledge.
Check the ingredients and their proportions, to get a better idea of what will serve best. The ideal potting soil, according to the information above, should
- Be light and fluffy, for better air circulation
- Have ingredients such as peat moss, pine bark, perlite, and other organic material for nutrients and water drainage.
Additionally, you can look for fertilizers and water-retention crystals, if your plant requires it.
Choosing the right potting soil can mean the difference between a healthy plant and a slowly dying one. Not only would the ideal potting soil ensure the plant’s health, but it will also make you a very happy plant parent!