Best Soil For Calathea (DIY Calathea Soil Mix Recipes)

If you want your calathea to thrive in your home, then providing the perfect potting soil is the first step you should take.

And it’s not easy to find the best soil for calathea especially when there are hundreds of options available.

But, you don’t have to worry.

In this article, I will be going through everything you need to know about choosing the perfect potting mix for your calathea plant.

It includes,

• What is the best soil for calathea?
• Why is soil important for calathea?
• How to choose the best soil for calathea?
• How to know if you are using the wrong soil?
• Calathea soil mix recipes
• Lot’s more.

So, that’s a lot to cover.

Let’s get started.

What Is The Best Soil For Calathea? (Short Answer)

Based on multiple research papers, the best soil for calathea is the one with very good drainage capability, water and moisture retention, acidic pH, well aeration, and high nutrient density. 

Components like peat moss, orchid bark, perlite, worm castings, or leaf mold mixed in a good ratio will be perfect for the calathea to thrive. You can add some activated charcoal to make the pH in the slightly acidic range.

Even though choosing the best soil for calathea seems to be easy, there’s a lot more to it. Read on to learn everything you should know.

Why Is Soil Important For Calathea?

It is very common for many beginner plant owners to skip the importance of soil when it comes to growing plants. I’ve seen a couple of my friends just planting any plant in their backyard soil.

That’s the last thing you can do to your calathea plant.

For a plant, the soil is one of the most important factors that determine its health and how fast it can grow in the current environment.

Soil holds all the necessary nutrients that a plant wants. And the nutrient requirements are not the same for all plants which imply different plants need different soil mixes.

Also, the soil is the one that holds the plant’s root system and provides stability. Not all plants have the same kinds of root systems, some have dense roots while others have loose ones. It further proves the fact that different plants need different soil mixes.

If you get your calathea’s soil right, then most of the plant problems that you are currently facing, like brown and curly leaves, stunted growth, etc will vanish in a couple of weeks. On the other hand, if the soil is wrong then you are slowly killing your calathea.

Now, the question will be how do I know if a particular soil mix is ideal for calathea or not? And, that’s what I’m going to explain in the next section. So, continue reading.

How To Choose The Best Soil Mix For Calathea?

When you are choosing the best soil for calathea plants, you should consider nutrient density, water holding capacity, aeration, pH level, and drainage capability as the main parameters. The perfect soil for a calathea plant would be the one that is very close to what they get in their natural habitat.

Since there are millions of potting materials and combinations available, it is practically not possible for anyone to test how a calathea performs in all.

Instead, scientists have decided to study the natural habitat of calatheas to understand why they are growing in that region and what are the unique characteristics of the soil in that particular region.

So, based on those studies, they have formulated a set of well-defined characteristics a soil mix needs so that calathea plants can thrive. 

Let’s discuss each one of those characteristics in detail.

1. Nutrient density

Nutrient density is nothing but the number of nutrients a particular soil mix can provide.

The three most important nutrients necessary for calathea plants are Nitrogen, Phosphorus, and Potassium. 

Most of the pre-made calathea potting mix will have these nutrients mixed in a healthy combination that’s tailor-made for calathea plants.

If you don’t want these nutrients to come from chemicals, then you can go organically and choose to add worm castings or leaf compost.  

These organic composts contain not only Nitrogen, Phosphorus, and Potassium, they also have a couple of additional nutrients like copper, zinc, cobalt, etc which will further enhance the growth of your calathea.

2. Water holding capability

Water holding capability is the ability of the soil to hold the required amounts of water or moisture so that the plant can survive without watering daily.

Generally, calathea plants need to be watered once a week during the growing season. So, the potting medium you choose for the calathea needs to retain enough water content for a week so that the plant won’t dry out between watering schedules. 

The water-holding capability and drainage capability of a soil mix are tightly related. The ideal potting mix should retain only the necessary amount of water and should allow the excess water to pass through drainage holes freely.

3. Aeration

Aeration is the ability of the soil to allow the free passage of oxygen to the roots. 

A well-aerated soil has enough pores and spaces between the materials so that the plant can breathe comfortably. 

On the other hand, a poorly aerated soil will deprive the plant of oxygen which further affects the transpiration and other plant processes leading to stunted growth and eventually killing the plant.

The main reason why you should not use your backyard soil for potted plants is the fact that they are not well aerated. The soil in most of our neighborhoods is damp and compact which does not allow free passage of air and water.

4. pH level

Based on a couple of research papers, the ideal pH value for calathea plants is around 6.5. Even though your calathea will grow without any issue when the pH is a little low or a little high, the maximum growth is recorded at 6.5 pH.

A pH value of 6.5 is considered to be slightly acidic, but close to being neutral. The main advantage of slightly acidic soil for gardening is that it provides the optimal balance of major nutrients and allows the plant roots to suck up the soil nutrients easily (Source).

But, at the same time, you should ensure that the soil pH is not going below 5.5 which is considered to be dangerous for plant roots.

Now you know what are the main parameters to look for in a soil mix for calathea plants. 

If you already have a calathea plant what if the existing soil is not an ideal one for your plant? Will the plant show any signs of distress?

The short answer is yes, and I’m going to explain those in the next section. Let’s move on.

How To Know If You Are Using Wrong Soil For Calathea?

If you are using the wrong soil mix for your calathea plant, then the plant will show symptoms like color change in leaves, curling and wilting, slow or stunted growth, always wet soil, hard and damp soil, etc. 

Some of these symptoms are common for other calathea problems like overwatering, root rot, etc. And, that is the main challenge with growing plants. Finding the real reason for a problem is time-consuming, but at the end of the day, all the problems are related to each other.

Let’s have a detailed look into each of these symptoms so that you can understand how these are connected with bad soil mixture.

1. Color change of leaves

It is very common that if a plant is under stress, then the effect will be seen on its leaves.

And, that’s true for calatheas as well. One of the common symptoms of the bad potting mix is discoloration, or in simple words, color change in leaves.

This is a common symptom for many plant problems including root rot, temperature stress, leaf burn, etc.

The reason for this symptom is very simple. If your calathea plant is sitting in the wrong potting mix that is very hard or damp, the roots won’t get enough oxygen and other nutrients to do plant processes. As a result, the plant starts to lose its green pigmentation and turn yellow and then brown.

2. Curling and wilting leaves

This is a condition similar to the color change, but instead of calathea leaves turning yellow or brown they will curl and wilt.

Wilting of leaves is generally considered to be the last stage before a plant starts to die.

Curling of leaves is also a commonly seen symptom for other calathea problems like overwatering, underwatering, severe heat stress, etc. So, check for the other signs before changing the soil just because some of the leaves are curling and wilting.

3. Stunted growth

When the majority of the leaves are already wilted, then the plant will be in a state of stress and stop producing new growth. 

It is quite understandable when a calathea plant is not able to suck oxygen and other nutrients, how can we expect it to grow new leaves?.

If you are seeing very slow growth coupled with too many curly or wilting leaves, it’s time for you to take action and repot the plant immediately. If not, even the stem of your plant will start turning brown as a result of drying. 

Once the majority of your calathea’s stem is brown, then there is no coming back. 

4. Hard, damp & wet soil

If you’ve read the characteristics of a good calathea soil mix, you know that it should have good aeration, water-holding, and draining capability.

When any one of these three parameters is missing, your soil will be wet even days after watering. In all the cases, the soil is not allowing the excess water to move freely and drain out of the pot through drainage holes.

Also, if the soil is always wet, then it must be hard and damp. All these three are interconnected. 

To know if your calathea soil is hard or damp, just poke your fingers into the pot a few days after watering your plant. If you had to put a lot of pressure to poke in, then your soil is probably hard and damp.

Always wet soil is also a symptom of overwatering and root rot.

5. Mushy roots & bad odor

If your calathea’s soil is always wet, then there is a high chance that the roots of your plant are already rotting.

Root rot is a commonly found issue related to overwatering your calathea. But, if your soil is very poor, it won’t efficiently drain the water resulting in a situation similar to overwatering.

If your calathea’s roots are decaying and rotting, then a bad rotten egg smell will come from the base of the plant. If you uproot the plant from the pot, you may see the roots have a mushy appearance.

Best Calathea Soil Mix Recipes

By now, you probably know whether your soil is the right mix or not for your existing calathea plant. If it’s right, then that’s great news. 

On the other hand, if your soil needs to be replaced, then you need to either purchase a premade soil mix made for calathea or get some raw materials and mix one yourself.

The DIY route is recommended because it allows you to fine-tune the composition of the soil mix based on the atmospheric conditions and care.

Before recommending calathea soil mix recipes, let’s have a look at the commonly used components in a healthy soil mix.

Peat Moss: If you got peat moss, then you are doing the best thing for your calathea plant. Peat moss provides good soil aeration, holds soil nutrients, and holds moisture between watering cycles without waterlogging.

Coco Peat/Coco Coir: If peat moss is not available in your country, then the next best soil ingredient for your calathea is coco peat or coco coir. It is the powdered version of the fiber-like thing found in coconut husks. It also holds all the characteristics of peat moss.

Orchid/Pine Bark: Orchid or pine barks are the outermost layers of stems of the respective plants. They are available as chips in different sizes. It is used to improve the aeration of a potting mix.

Perlite: Perlite is a glass-like naturally occurring mineral commonly found near active volcanoes. The commercially available perlite is the heated version of the natural perlite which is full of air inside. The highly porous nature of perlite is the reason why they are used in the potting medium of indoor plants. They can improve the aeration and water drainage capability of the soil mix.

Vermiculite: Vermiculite is also a naturally occurring glass-like mineral that has similar characteristics to perlite. Compared to vermiculite, perlite has better aeration and drainage capability, but still, if you can’t get perlite, then vermiculite is a viable option.

Worm Castings/Compost: Worm castings are the soil or mud that has been thrown by a lugworm or an earthworm after passing through the worm’s body. Worm castings are highly nutritious with a good concentration of Nitrogen, Phosphorous, Potassium, Copper, etc. If worm casting is not available for you, Leaf mold or compost will be a good alternative.

Charcoal: Charcoal is used to retain nutrients and improve the drainage capability of the soil mix. If you don’t have any other ingredients mentioned above for improving drainage, then you can opt for charcoal.

Now you know what are the most commonly used ingredients in a healthy calathea potting mix. So, let’s have a look at some of the different combinations we can make using these ingredients.

Calathea Soil Recipe 1

• Orchid/Pine Bark (25%) – Improves aeration and drainage.
• Coco peat/ Coco coir (25%) – Improves water/moisture retention.
• Perlite (20%) – Improves drainage of water.
• Worm castings (15%) – Adds nutrients to the soil mix.
• Charcoal (5%) -Absorbs excess water.
• Sand (10%) – Holds everything together

Calathea Soil Recipe 2

• Orchid/Pine Bark (25%) – Improves aeration and drainage.
• Peat Moss (30%) – For moisture retention and nutrients.
• Vermiculite (20%) – For improving drainage and aeration.
• Leaf mold/compost (15%) – Adds nutrients to the soil mix.
• Sand (15%) – Holds everything together

The major advantage of making your potting soil for calathea plants is the fact that you can change the composition based on the conditions you provide.

For example, if the humidity is too high or you are someone who always tends to overwater, then you can increase the concentration of materials that have high drainage capabilities. 

On the other hand, if you tend to underwater your plants often then increase the amount of water holding materials.

If you don’t have access to all these different ingredients as individual packets or don’t have enough time to mix them, then I highly recommend you to get some ready-made potting soil and add perlite or vermiculite into it. 

The recommended ratio is 30% of perlite and 70% of potting soil.

Calathea Soil Mix – Frequently Asked Questions (FAQs)

In this section, I will be going through some of the most commonly asked questions regarding the best calathea soil mixes.

Wrapping Up

In this article, we’ve covered everything you need to know about choosing the best soil for calathea plants.

We already saw that the best potting soil for calathea is the one that has the good water-holding capability, drainage capability, well-aerated, and a slightly acidic pH value.

Potting mixes with peat moss, coco peat or coco coir, leaf mold, and perlite in healthy ratio tick all the required characteristics to be the best soil for the calathea plant.

Sources

1. Research on Soil Acidity in Agriculture Victoria Journal, Australia.
2. Biochar Made From Green Waste As Potting Media For Calathea in Scientia Horticulturae Journal.
3. Composted Green Waste For Calathea in Plos One Journal.