Choosing the Right Soil For Indoor Plants
Are you a houseplant parent who is overwhelmed by the many soil choices? If so, you're not alone! Like us, plants have various needs, and it's essential to be aware of what they are, such as the right amount of light, water, and optimum temperature.
Another critical thing to remember for healthy plants is knowing which soil is best for your houseplants. But how can you possibly choose when your local garden center is jam-packed with different options?
Here, I'll break down how to choose suitable soil for indoor plants and what to look for. I'll also cover which soil type is best for each type of plant, and I've added a section on how to make your own soil.
So, if you'd like to know all about choosing the correct potting mix, scroll down to find out more!
How Do You Choose The Best Potting Soil?
When it comes to choosing the right soil mix, generally, you'll need:
A specially formulated soil for houseplants: Don't just scoop some from the backyard, or your plants will not grow properly.
A pre-made mix: You could use a mix specially made for the houseplants you have, a general mix for hardier plants, or add an amendment to the mix to boost aeration or drainage.
OR a homemade mix: For healthy, strong plants, you could create your own soil and customize it if you have different plants. More on that later!
What To Look For When Choosing Indoor Potting Soil
I know it sounds odd, but the best soil mixes for houseplants don't contain soil at all! Potting soil mixes aren't sterile, and they may contain weed seeds or pathogens. Plus, it can be far too heavy for houseplants.
Many potting mixes for houseplants combine perlite, sphagnum peat moss, and organic material like worm castings (meaning worm poop).
Remember choosing the right soil and knowing when to repot your plants can also mean healthy plants and help prevent bugs!
Do you need organic potting soil?
You'll find two types of organically made soil. The first is the type that comes from plants, and the second is the type that doesn't contain artificial fertilizer. The first type of organic is more important for houseplants because, after all, you're not going to be eating your Scinapsus!
However, if you want to avoid artificial fertilizers or you want complete control over which fertilizer your plants are exposed to, stay away from mixes such as the Miracle-Go Indoor Mix.
Instead, look for a brand labeled as either OMRI-certified organic, or a variety that doesn't feature artificial fertilizers on the ingredients list.
What about peat moss?
The issue with peat moss, also known as sphagnum moss, is that it's not sustainable. Although it will regenerate eventually, it can take what feels like forever, and natural peat bogs can't keep up with how fast they're harvested.
Because of this, some countries, such as the UK, are moving towards prohibiting the use of peat moss in soil mixes.
Coconut coir is becoming more commonly used in soil mixes because it provides all the benefits of peat moss but is more sustainable. Coco coir is made of coconut husks which are typically considered waste matter.
What does it contain?
If a particular bag of soil doesn't have an ingredients list, skip it and pick something else. Certain potting mixes contain styrofoam and other components that won't make your plants happy!
Plus, an ingredients list will tell you if the mix already contains a fertilizer, so you know if you need to add your own or not.
What is The Best Homemade Soil For Each Houseplant?
Flowering and tropical plants
A combination of perlite and coco coir in your potting mix will provide a great balance of adequate drainage and moisture for tropical plants. A good soil mix for these plants could include:
35% pine bark
35% composted wood chips or bark - or any other high-quality compost that you have spare
20% perlite
10% coco coir
Succulents and cacti
Many succulents and cacti thrive in soil with good drainage because they're used to dry, arid climates. A good DIY potting mix may include:
40% course sand
35% coco coir
20% perlite
5% worm castings, compost, or other natural fertilizer
Seed starting
Many seeds love heat, moisture, and small amounts of nutrients. Coco coir can retain moisture in homemade potting mixes, while a spot of worm castings or compost will provide the proper nutrients.
A homemade nutrient-rich potting soil for seed starting should include:
75% coco coir
10% vermiculite
10% perlite
5% worm castings or compost
How To Make Your Own Soil For Indoor Plants
The great thing about creating your own soil for houseplants is that you can make it your own. Once you're familiar with what the ingredients do, it's easy to adjust the mix to meet each plant's needs.
To make your own potting mix, you'll need:
A large tub
A soil scoop, trowel, or even a big spoon
Airtight container for excess soil
To make your soil, simply pour your ingredients into the tub, mix it thoroughly, and you're ready to re-pot some houseplants!
Here are some potting mix ideas to get you started:
Potting soil, sand, and pumice or perlite: This creates a porous mix suitable for cacti and succulents.
1/4-1/2 drainage ingredient such as orchid bark or coco coir and 1/2/-3/4 potting soil: This combination will provide a potting mix that's rich but well-draining that's suitable for various tropical plants.
Equal parts pumice, coco coir, and orchid bark, with small amounts of humus and horticultural charcoal: This is a mix I recommend for aroids like monsteras and philodendrons. If you don't have pumice, you can use perlite instead, but be aware that it'll float to the top eventually.
FAQs
What is the best type of soil for indoor plants?
The best potting soil for indoor plants is different for each plant because they all have different original habitats that will determine the soil preference. However, all houseplants require water, fertility, airflow, and strong soil stability.
Can garden soil be used for houseplants?
Unfortunately, no. Garden soil, or topsoil, is far too dense and heavy for indoor potted plants. Eventually, it will become too compacted in the pot, suffocating the plant roots. Instead, you'll need proper potting soil.
Can I use pre-packaged soil for my houseplants?
For most indoor potted and container plants, yes, you can. But, certain types of plants require components that standard mixes can't provide. This could be quick drainage, better water retention, or more aeration.
If that's the case, you can buy a standard potting mix and add the amendments that your plants need.
Final Thoughts
Choosing suitable potting soil for indoor plants is a vital first step in maintaining the health and strength of the plants. Before you buy a general potting mix, it's a good idea to ask a local nursery (or PlanterSam) for soil recommendations for your climate zone and plant type.