Calathea louisae, known for its air-purifying ability and decorative leaves, stands out as one of the most in-demand house plants anyone would climb mountains to search for. But, would it still be pleasing to the eye when some of its leaves start turning brown? Absolutely not!
In general, Calathea louisae leaves turn brown due to 1) dry soil, 2) overwatering, 3) low humidity, 4) poor water quality, 5) fertilizer buildup, and 6) pests. However, these causes can easily be prevented and/or resolved.
But do not worry, I will not just leave you with the causes of brown leaves in Calathea louisae! I have generously spread golden hacks in this article for you to find—just like Easter eggs! So prepare your basket and let us go!
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Excessively dry soil can still deprive Calathea louisae leaves of getting water to keep biological processes running. This is despite the fact that Calathea species are from the tropics. With less water, the leaves will start to dry and eventually turn brown.
Let me explain this using a parallel situation.
Have you ever purchased a cut flower like rose, sunflower, and lilies? If yes, I know you can answer my next question. What is the first thing you have to do if you want to display those flowers for at least, let’s say, 3 days?
You got that right! Put them in a vase with water.
This is a reflection of how important water is, for our plants. If you are a fan of experiments, you can try comparing how long a flower grown in water lasts versus another without a water source.
Generally, the first symptom of water shortage in Calathea plants is wilting. When exposed to this environment for a long period of time, the leaves will eventually turn brown. Other signs include drooping or curling leaves.
Golden Hacks: When caring for Calathea louisae, check the top 1-2 inches of the soil. If it feels dry, give your Calathea louisae plants plenty of water. Do this until the lowest portion of the soil is already wet. Afterward, you can stick to only watering them every 2-3 days.
At this point, if you are worried about overwatering, I have allotted a whole section below for both of those concerns. So let us move forward!
Overwatering can result in root rot that weakens the immune system of the Calathea louisae plants, leading to yellowing, and further, browning of the leaves.
You will know that you are overwatering your plants if the top portion of your soil is always moist. You must avoid getting to this point. This is because a wet environment is a breeding ground for harmful microorganisms.
Bacteria and/or fungi may develop and infest the roots of an overwatered Calathea louisae. When the roots are attacked by these microorganisms, the whole plant is at stake. Stems and leaves might also reflect alarming symptoms such as yellowing, browning, and ultimately, wilting.
You need to balance keeping your soil moist but not soggy. To do this, let the top 2 to 3 inches of your soil dry out before watering again.
Golden Hacks for Overwatering: It would help to check the roots first if they are already infected with root rot. If the roots are brown and smelly, your roots are rotting! If there is only a small rotting portion, you may cut that part, and repot your plant with new soil. Most importantly, never allow your Calathea louisae plant to sit in water.
Aside from the soil, Calathea louisae leaves can also absorb water through the air. When there is low humidity, the leaves will not have enough source of moisture. Without an ample source of water, the leaves will be dehydrated and eventually turn brown.
Calathea louisae is native to the American tropics. In other words, it demands a lot of humidity in its environment.
Maintaining a relative humidity of 50% and above is a wise way to keep your Calathea plants a lively green.
Golden Hack: You can use an essential oil diffuser to make your indoor garden humid. But, instead of oils, fill it with distilled water. Misting sprays are not recommended because they give off larger droplets which can be breeding grounds for bacteria and fungi.
Here is an essential oil diffuser on Amazon that you can use in your indoor garden.
If you have a lot of plants in a bigger room, this humidifier might be the best option for you.
Avoid using tap water when watering Calathea louisae because it might contain chlorine, fluoride, mineral, and salts, which tends to build up in the soil. When this happens, water strives to move toward the upper part of the plant. Eventually, browning of leaves occurs as a result of the deprivation of water.
Minerals and salts can build up in your soil if you use tap water—a prominent source of these elements.
Aside from tap water, it is also not advised to use soft or hard water. These water types are also sources of minerals like calcium and magnesium.
Golden Hack: In watering Calathea louisae, use distilled water instead of tap water. This is because the distillation process it undergoes gets rid of naturally-occurring contaminants like minerals which prevent the browning of Calathea leaves.
Learn more about water in our article explaining the different water types.
Calathea louisae is sensitive to synthetic fertilizer. When provided with excessive nutrients, leaves turn brown as a result of mineral, salt, or fluoride stress.
Lack and excess are concepts in the Calathea world that are not best for favorable plant growth.
When there is excess fertilizer in your soil, it is difficult for water to mobilize. This is because the build-up of salts and minerals hinders the water from approaching the plant roots. In this situation, the abundance of fertilizer acts like traffic congestion. And we do not want that!
Again, without enough water access, the leaves become dry and eventually turn brown.
How can you prevent this?
Golden Hack: When applying fertilizer, start with a weak solution by diluting your fertilizer well. Furthermore, you can also use organic fertilizer like worm castings. This is because organic fertilizers are not as strong as synthetic fertilizers in carrying salts and minerals.
Explore more about the differences between fertilizer types in our article about organic vs inorganic fertilizers.
Pests like aphids, spider mites, and mealybugs can also be a reason for browning as they suck nutrients out of the leaves.
These pests are usually infesting the underside of the Calathea leaves. Webs, silver streaks, and dark poops of bugs are some of the signs that insect pests are present in the plant.
Golden Hack: When any of these signs are present, you can spray your Calathea with neem oil which is an organic pest control agent.
The product below is an effective neem oil spray available on Amazon. I’ve been using this since the first pest infestation in my indoor garden and it works well!
Should I cut the brown leaves of Calathea plants?
Cutting the brown leaves of Calathea plants is a practical way to improve both its decorative purpose and growth process. When these leaves are cut, the plant will divert spending its resources such as water and sugars to develop new leaves. Remember to cut the affected leaves down to their bases to give space for new leaves to grow.
Why are the leaves of my Calathea crispy?
Having crispy Calathea leaves is a sign of underwatering. This symptom usually starts from the leaf edges and then gradually dominates the whole leaf, inward. When this happens, give your plant plenty of water. If the crispiness persists, you can already cut that specific leaf to promote the growth of new leaves.
Do Calathea plants like direct sunlight?
No, Calathea plants do not prefer direct sunlight. Rather, they grow best in bright, indirect sunlight, making them perfect houseplants. Direct sunlight raises the soil temperature, which can further lessen the amount of water in the soil. With a lesser water source, the plants might exhibit yellowing, curling, browning, and wilting.
What temperature is best for Calathea plants?
It is recommended to keep the growing temperature of Calathea plants between 64 to 75 °F. Consistent exposure to cold surrounding temperature can cause leaf browning as it slows down biological processes for Calathea leaves. By contrast, hot temperatures negatively affect factors such as soil temperature, water access, and humidity.
The browning of Calathea louisae leaves can be attributed to five factors namely soil dryness, watering frequency, relative humidity, water quality, fertilizer build-up, and pests.
Dry soil deprives the plant roots of Calathea louisae of water, resulting in leaf drying, followed by browning. Overwatering promotes root rot that weakens the immunity of the Calathea plants. When this happens, stems and leaves might soften and eventually turn brown. High humidity is required for Calathea since they are naturally from the tropics.
Mineral build-up is also a concern arising from the usage of synthetic fertilizers and tap water which is a known source of salts, minerals, chlorines, and fluorides. Lastly, insect pests such as aphids, spider mites, and mealybugs can also cause browning as they suck nutrients in leaves.