What is the best potting soil for indoor plants? This is one of the most common questions any gardener will aske themselves at one point or another.
Often, it happens when you’re starting out. But it could very well occur when you just brought home or bought a new plant online that’s different from those you already own.
In this article, I’ll go through everything a home gardener needs to know about potting soil and reveal the best potting soil for indoor plants.
Potting Mixes / Growing Medium
Most plants you’ll find will need soil to survive.
In short, they need a growing medium. That is, somewhere that will allow them to grow in.
There are a few reasons for this:
- Their roots need to grab hold on to something underneath. This provides your plants with a stable foundation so they won’t just topple over in strong winds. A strong root system also allows them to not be easily pulled out of the ground.
- Soil provides them with nutrients and water. Their roots absorb both components from the soil.
The problem is, it’s not a good idea to use soil from your garden for your houseplants.
- It contains bugs, insects and pests you don’t want in your home
- Outdoor soil may contain disease which will kill your plants
- Regular soil is heavy. This can become a big problem if you want to move a 4-foot plant to another room.
- It hardens and congeals. This compacting makes it hard for your plants to receive proper moisture as well as air.
So, what’s an indoor gardener to do?
Get potting soil.
What is Potting Soil?
Simply put, potting soil is a man-made “soil” that’s specially designed for indoor plants.
Why the quotations?
That’s because potting soil isn’t soil at all. Instead, it’s mostly composed of perlite, peat moss and tree bark.
But, just by looking at it, you’d never know the difference between potting soil and the soil in your garden.
Developed in the 1960’s potting soil has become the go-to growing medium for houseplants. That’s because it’s very effective for growing plants. Add to that it is lightweight, free of weeds, pests and diseases.
This makes it a better option to regular soil when it comes to indoor gardening.
What Is The Difference Between Potting Soil And Potting Mix?
Before going any further, one thing worth noting is that the terms potting soil and potting mix are often used interchangeably.
And, in most cases, they’re the same thing.
But, in some instances, there are products labeled potting soil that are actually soil.
You don’t want that.
Instead, make sure that potting soil/mix your get is soil-less. Doing so eliminates all the negative things about the soil mentioned above.
For this reason, it’s important to read the label before buying.
That said, there are situations where you may want to consider soil-based potting mixes.
For example, if you want to grow plants in containers but keep them right outside your home. If they’re on the balcony, porch or deck, then the extra dirt or weight may not be much of an issue.
Another reason to choose soil-based potting mixes is if the plants you want to grow require a lot of water.
Soil-based potting mixes retain water much better than soil-less ones. As such, they reduce your watering frequency especially with bigger, water-hungry plants.
That said, when choosing soil-based potting mixes, do make sure that they’ve been sterilized before packaging.
What Does Potting Mix Consist Of?
As mentioned, potting soil/mix is mostly made of perlite, peat moss and tree bark. But, they also contain many other components that can vary depending on the type of potting mix you select.
- Wood chips
In addition to this, potting mixes are heat-treated or steamed in high temperatures before packaging. This kills all the micro-organisms and potential disease that’s in them.
The feature makes ideal for indoor gardening.
Do I Need to Add Fertilizer to Potting Mix?
The one drawback to potting soils is that they don’t have nutrients in them. You can already probably tell just by looking at the list of components above.
Here’s where you’ll need to make a decision.
Many potting mixes sold in stores come with fertilizer added to them. This is to make up for this shortcoming. But, not all do.
So, you can opt to buy one that’s pre-packaged with the fertilizer in it. Or, one without.
If you choose the latter, you can add fertilizer yourself or create your own. Either way works.
If you decide on the former, you’ll likewise need to make another decision.
Most potting mixes that include fertilizer come in two forms:
- Starter Charge. Potting soil that comes with a starter charge or fertilizer means it comes with enough to get you started. That is, you won’t need to add fertilizer the 2-3 times you water. But, you’ll need to do so after that since the starter dose has been depleted by then.
- Slow Release. This contains more fertilizer. But again, you’ll need to add your own later on. After 3 weeks to a month or so, it’s gradual release will be used up.
What are Special Potting Mixes?
For most plants, you’ll likely be using an all-purpose potting mix. This contains your basic tree bark, peat moss, vermiculite or perlite. But, some plants do better with specific ingredients.
As such, you’ll find a couple of special potting soil designed just for them.
Cacti and Succulent Mix
These mixes drain water very quickly. They’re designed to do so because succulents and cacti don’t like wet environments. That’s due to them being used to warm and dry conditions.
Orchid and Bromeliad Mix
Most orchids and bromeliads are epiphytes. That is, they don’t grow on soil. Instead, they cling other plants like trees. For nutrition and sustenance, they rely on water and air.
As such, they prefer a growing medium that drains very quickly and allows for a lot of air to pass through.
- How to Prune Plants
- How To Repot Your Houseplant
- How to Water Indoor Plants
- Indoor Plant Temperature & Humidity Needs
- Plant Pot Types and Sizes
- Plant Propagation for Beginners
How to Choose Good Potting Soil
When it comes to choosing potting soil, you want to keep a few things in mind.
- Choose soil-less for your indoor plants
- It should be fluffy and light
- Choose the right mix for your plant. Different plants will prefer different kinds of potting mixes. While the all-purpose mix works well for most houseplants, there are special mixes for various kinds of plants.
- Decide whether you want one with fertilizer or not. If so, pick between starter charge or slow-release forms.
Below is a chart showing the different types of potting soil commonly available.
Each of them has their specific uses which makes it suitable for certain kinds of plants.
Additionally, it is useful to know the water holding capacity of different kinds of soil and components you’ll be using to make your DIY potting mixes.
Here’s a chart that shows which soils hold more moisture and which ones drain water faster.
This way, you can match them with water-loving plants or plants that are susceptible to overwatering or waterlogging.