Proper care for a Calathea houseplant starts from the bottom up, and you can set yourself up for success by rooting yours in the right container and growing medium. If you’ve struggled to keep these flashy but fragile plants alive, it might be time to take another look at the soil environment you’re providing. So, what soil is best for Calatheas?
Calatheas do best in slightly acidic soil that drains well but remains a bit damp between waterings. A standard houseplant potting mix will probably be too water-retentive for these fussy plants, but you can boost the drainage by adding coarse ingredients like perlite or tree bark. Mixing in some light and fluffy material such as coconut coir is also a good idea.
As for the container, the most critical element is drainage holes; a pot full of standing water is a quick way to kill your Calathea. The material doesn’t matter as much, though if you frequently overwater your plants, you might want to pick a terra cotta pot to help the soil dry faster. Repot once every 1-2 years, increasing the size of the container an inch or two each time.
Why Is Soil Quality So Important For Calatheas?
It’s vital to give your Peacock Plant the right potting blend because it’s incredibly vulnerable to both overwatering and underwatering. More Calatheas are killed by improper hydration than any other single issue. And the soil plays a crucial role in regulating how much moisture your plant’s roots receive.
A blend that drains too quickly may dry out between waterings, which is very stressful for a moisture-loving Calathea. These tropical plants don’t tolerate dehydration well. It can leave them vulnerable to pests and infections and even kill them outright if it persists long enough.
On the flip side, a slow-draining mix often becomes so soggy that the air pockets inside the pot get filled in. That’s bad for your Calathea’s roots, which need room to breathe. Poor drainage also lets mineral salts accumulate in the soil more quickly, which places further strain on the roots.
Even more concerning is the possibility of root rot. Waterlogged soil provides an ideal environment for fungi and bacteria, and when these microorganisms multiply out of control, they can invade your Calathea through its root system. Severe cases of root rot can reduce a gorgeous Pinstripe Plant to a heap of mushy stems and withered leaves in under two weeks.
The good news is that if you get the right blend of soil, caring for your Calathea becomes a lot easier. A healthy mix offers good drainage while holding onto enough water that the roots won’t dry out. Let’s talk about how to hit that perfect balance.
Store-Bought Mix For Calatheas
The simplest way to get a decent growing medium for your Calathea is to use a pre-mixed potting soil that’s intended for African Violets. These fuzzy-leafed indoor beauties are almost as picky about their watering needs as Calatheas, and they thrive in similar conditions.
It’s up to you whether to use a blend with synthetic fertilizer mixed in; just remember which choice you made so that you can decide whether to give your Calathea some supplemental nutrition later on.
Creating Your Own Calathea Mix
So if off-the-shelf African Violet mix works well enough for Calatheas, why do some growers blend their own?
There are a few reasons. First of all, “well enough” isn’t the same as “perfectly.” Most commercial soils are still a bit slow to drain compared to a really good homemade potting mix. This may be deliberate; garden retailers tend to err on the side of water retention since they assume that the average customer is likely to forget about watering at times.
More attentive plant parents often find that they need to enhance mass-market potting soils with some amendments in order to get the drainage just right.
Another reason is environmental concerns. The average store-bought potting mix includes a hefty dose of peat moss. Unfortunately, this is a non-renewable resource that’s harvested from ecologically significant wetlands. Many people prefer to create their own blends using more earth-friendly materials.
Last but not least, there’s the simple joy of experimentation. There’s no better way to get good at houseplant care than by trying different strategies and learning what works best for your plants.
Soil Ingredients for Calatheas
There are two main types of ingredients to consider when you’re putting together a potting blend for your Calatheas. The first category is coarse elements that space out the mix to increase aeration and drainage. Some examples include:
- Bark chips. These are available in several grades, from fine shreds to thick chunks. They’re often listed as “orchid bark” since they’re a popular potting medium for orchids. Usually derived from conifer trees, they can help to acidify the soil, which Calatheas appreciate.
- Perlite. These are the crumbly white bits that make an appearance in most store-bought potting soil. Perlite is made of porous volcanic glass that helps soak up and hold moisture, and its coarser varieties are great for adding air pockets to your growing medium.
- Coconut husks. The thick and fibrous outer part of a coconut shell. It’s quite airy and fluffy when chopped up.
- Crushed pumice. Much like perlite, but often available in even bigger chunks.
- Hardwood charcoal. This also has similar properties to perlite, though it’s not as heavy and is potentially a more sustainable choice. Note that we’re talking about special-purpose horticultural soil, not grill-ready briquettes.
- LECA. A fancy acronym for spheres of porous expanded clay. LECA is usually used in semi-hydroponic setups, but it’s also good for spacing out a potting mix while retaining some water.
The other type of ingredient is spongy organic material, good for soaking up excess liquid and maintaining a damp environment around the roots. Some popular options:
- Sphagnum moss. Though this term is often used interchangeably with “peat moss,” some types of sphagnum are harvested more sustainably. Those varieties are more pH-neutral and less nutrient-rich, but their water-retentive properties are similar.
- Coconut coir. Also called cocopeat, this is the standard eco-friendly replacement for moss. Essentially an upcycled waste product from coconut harvesting, it’s fluffy, absorbent, and great for potting soil.
- Compost. Great if you want to add some organic nutrition to your Calathea’s soil. We recommend vermicompost, also known as worm castings, which helps to aerate your mix at the micro-level.
Putting Your Calathea Mix Together
Over time, you’ll most likely experiment with different mixes for your Calatheas. The basic rule of thumb is to combine roughly equal proportions of the two classes of ingredients described above. That should produce a growing medium your Calathea will adore.
One solid recipe to get you started includes 20% African Violet potting soil along with 40% perlite and 40% coconut coir. If you want to do away with store-bought mix entirely, try 40% coconut coir, 25% orchid bark, 25% perlite, and 10% vermicompost.
Toss on some dependable garden gloves and mix all your ingredients together thoroughly in a big plastic tub. If you use perlite, make sure you’re working in a well-ventilated space, and you might also want to wear a painter’s mask. Perlite often gives off quite a bit of dust when you pour it out.
Older guides sometimes recommend layering potting mix ingredients to place the coarsest materials on the bottom. We do not advise this approach. Without the finer material at the base to soak up excess liquid, you could wind up with standing water around your Calathea’s roots – precisely what you’re trying to avoid.
Can You Grow Calatheas in Just LECA?
The semi-hydroponic approach is an alternative way to raise houseplants that’s gained some popularity in recent years. Semi-hydro replaces the entire soil mix with a jar or pot of some uniform, sterile, moisture-wicking substance (LECA, the clay spheres we mentioned in the section on soil ingredients, is the most popular medium). The base of the jar is filled with water, but the growing medium provides a buffer to keep the roots from sitting in the liquid and getting mushy.
This technique offers a few advantages:
- Humidity. The water at the base evaporates and moves easily up through the large spaces between the LECA spheres. The result is a more humid environment immediately around the plant.
- Ease of watering. Since the roots can soak up as much or as little as they need from the constantly damp medium, there’s little risk of giving the wrong amount of water.
- Cleanliness. It’s much easier to sanitize a bunch of smooth clay spheres than a mix of organic ingredients and soil, so a properly prepared semi-hydro setup can reduce the risk of disease.
- Control. If you love to experiment with your plant’s growing conditions, you may appreciate the ability to make precise adjustments to water and fertilizer levels. And semi-hydro doesn’t require drainage holes in the container, so you can use transparent glass jars, which allow you to directly monitor the health of the roots.
- Aesthetics. The way that a plant’s roots wind through a jar of LECA spheres can be quite cool to look at.
The main drawback is that you have to actively regulate the pH and nutrient levels. Potting mix has some ability to buffer the acidity level in the container, but LECA does not. And you can’t simply mix in some slow-release fertilizer or worm castings and forget about it – you’ll need to provide regular doses of liquid nutrition.
LECA is also more expensive than traditional potting mix, though once you’ve bought it, you can clean it and reuse it again and again.
So will this method work for Calatheas? The answer is yes…if you can get through the transitional phase. Calatheas are very vulnerable to transplant shock, and this risk is even more pronounced when moving them from a soil medium to LECA. That’s because your Calathea has to grow an all-new set of specialized water roots to function in a soilless environment. These young roots often have a hard time adapting to LECA at first.
To improve your Calathea’s odds of success, try placing it in a jar of pure water for a few weeks before moving it to semi-hydro. This will allow it to grow a robust set of water roots that can more easily take hold of the clay.
We don’t recommend trying to root your Calathea in LECA unless you already have some experience with semi-hydroponics. These aren’t beginner plants in any sense!
Want to keep learning? For more information on growing plants in LECA, read this article.
Choosing the Right Pot For Your Calathea
Once you’ve settled on the right growing medium for your Rattlesnake, Peacock, or Pinstripe Plant, you need a container to hold it. The good news is that just about any kind of pot will work as long as there’s a hole or two through which water can drain.
The only other consideration is what material to choose. Unglazed terra cotta is a good choice if you tend to err on the side of overwatering. It’s porous, allowing water to evaporate through the walls so that the soil dries out faster.
On the other hand, if you frequently wake up in a cold sweat realizing that you haven’t watered your plants in weeks, you might want something a little more tightly sealed. Glazed clay, plastic, and fiberglass pots hold in moisture better than terra cotta, and they’re sold in a much wider range of colors and shapes.
What if you have your heart set on a beautiful container, but it doesn’t have any drainage holes? Good news: you can still use it as a cachepot. Root your Calathea in a slightly smaller pot with better drainage, then slide that inside the prettier container. Always remember to take the plant out of the cachepot before watering and let it drain before putting it back.
Repotting Calatheas – What Size Pot to Use?
It’s the lament of every parent: you provide the perfect home for your babies, and because you did such a good job, they outgrow it and move on. The same thing will happen with your Calathea and the lovely pot you picked out. But how do you know when it’s time to repot? And how much room will your plant need to expand?
Healthy Calatheas grow reasonably quickly, and if you give yours everything it needs, it will require repotting in a year or two. The plant may alert you that it’s time to move by slowing down its growth, developing brown leaf tips and edges, or poking roots out through its drainage holes.
It’s best to avoid letting it get to this point if possible – these are signs that your Calathea is root bound, meaning it’s gotten cramped in its current pot.
Don’t use an overly large container when repotting. Size up 1-2 inches in diameter from the previous pot. That way, your Calathea will have room to spread out without being overwhelmed. Use fresh potting mix; the old stuff will probably be depleted of nutrients and may have an accumulation of mineral salts.
Final Thoughts
A good potting mix is the literal and figurative foundation of proper houseplant care. Now that you know what kind of soils and containers your Calathea loves, you can create the plant equivalent of a stately manor home – which is just what this botanical princess expects.