Calatheas are beautiful house plants loved for their gorgeous and showiest leaves. However, keeping the foliage in ideal shape admired is no easy task.
One of the main issues many people face with the Calathea plant is leaves turning brown. No one like to see the desirable green leaves lose their color prematurely.
So, why is your Calathea leaves curling and turning brown? Common reasons your Calathea’s leaves are turning brown on the edges include tap water quality, fertilizer, underwatering ( indicating an insufficient, improper, or inconsistent watering), and low humidity (meaning that the air is too dry)
You are likely to see leaves browning on the tips, at the edges, or in the middle-characterized by dry spots. If the situation is not so bad or just one or two leaves show this issue, you can ignore it, but if several leaves are browning, it may indicate something serious.
This article aims to shed light on what causes the browning of leaves and what steps you can take to fix and prevent future occurrences.
If you are interested in exploring How To Properly Grow And Care For Your Calathea White Star, I encourage you to read this helpful guide.
Why The Leaves Of Your Calathea Plants Are Browning?
If you want your Calathea plant to produce near-perfect leaves that create a sense of awe among your visitors, you will need to provide the plant with perfect conditions and excellent care.
Occasionally, you will encounter a few cases of dry brown tips and a small number of brown edges, even with proper care. Here are the reasons for Calathea browning leaves.
1- Underwatering Your Calathea Plants Might Cause Browning
Every plant leaf needs water to keep the cells healthy. Underwatering will make the leaves curl, dry up, and turn brown.
So, ask yourself when last you watered your Calathea plants; if you do not remember, the chances are you are underwatering. We know life is busy, but if you care about your house plants, you want to create a watering schedule and religiously follow it.
Calathea plants need weekly watering, but the frequency could also be influenced by factors such as plant size and environmental conditions.
But How Do You Know It Is Time To Water Your Calathea Plant?
Like most house plants, stick your finger 2 inches into the soil to establish the dryness level. If you feel the soil is dry, water them immediately because Calatheas are not drought-resistant plants and could turn brown faster.
Other signs such as droopy, curling, or yellowing leave point to underwatering, so you want to check that.
Besides using your finger to test the level of soil dryness, you can also use a soil meter to determine moisture content. You can find this equipment at a nearby garden center or online store.
How to fix underwatering?
The method you will take to correct underwatering depends on how long you have stayed without watering.
You can deep soak your Calathea plant if you realize you are behind schedule in your watering. You may be behind your watering schedule for days when you go for an extended vacation or away from home for some time.
If that is the case, the soil may be hydrophobic, so you can submerge the plant pot in a sink or a bathtub with lukewarm water for approximately 10 minutes instead of using a watering can or hose.
Remove the pot from the sink when you see air bubbles, and allow excess water to drain via holes at the bottom. Confirm if the soil is moist with your fingers. If it does not feel wet enough, repeat the process.
After soaking the pot, place it in a cool location, and within no time, your Calathea will look healthy.
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2- Low Humidity
Since Calatheas grow in the tropical forests of South America, they thrive in places with high humidity levels. Generally, most Calatheas do well with at least 50% humidity; however, some delicate species like Zebrina, Orbifolia, and Medallion need above 50% humidity.
If humidity levels drop below 40%, you may start to see Calatheas leaves turning brown on the tips and spreading across the leaf.
Other signs of low humidity may include leaves turning yellow and becoming crispy and droopy, especially if the situation continues for some time. If you see these signs, we advise you to measure the humidity levels of your room and take corrective actions.
But How Do You Measure Humidity Levels In Your House?
One way is to use a hygrometer to determine if the humidity levels in the room are suitable for the Calathea plant. Alternatively, you can use the ice cube method to test humidity.
Using The Ice Cube Method To Test Humidity.
Place some ice cubes in a glass, pour some water, stir and let it sit for a few minutes. Moisture should form on the glass wall; however, if you don’t see this, you know the air in the room is very dry.
How do you improve the humidity levels of your room?
You can use pebble stones to improve your humidity temporarily, but it is essential to repeat the process several times to maintain the effect.
Alternatively, you can group the Calathea plants and hope the moisture they lose through transpiration will create a microclimate in the room. This method can increase humidity by approximately 5%, meaning it may not be effective if the air in the room is very dry.
Nevertheless, many people have found that a humidifier is the best way to enhance humidity. A humidifier helps to saturate the air and prevent leaf browning.
You also want to use your humidifier in a specific room instead of open air. You can improve the humidity of an open area, so keep your plants in one room and humidify it.
3- Over-fertilizing Might Cause Your Calathea Leaves Turning Brown
We know that plants need fertilizers to grow healthy; however, fertilizer can be a source of stress for your plants if applied excessively.
Excess fertilizer causes a build-up of salt, which may cause the leaves to turn brown, making them susceptible to diseases and pest infestation.
So How Do You Ensure You Are Not Over-Fertilizing?
The general rule is to fertilize your Calathea plants once every four weeks during their growth period (in the spring and summer).
However, when the plants go dormant in winter, fertilizing is unnecessary. So, you could avoid applying fertilizer during this period. If you must use fertilizers during winter, ensure you dilute the fertilizer.
Signs Of Over-Fertilized Calathea Plant
Besides browning at the margin and tips of the leaves, you may also see yellowing and wilting at the lower side of the leaf. Other signs include white crust or salt deposits on the potting soil, signifying you are overfeeding the Calathea plant.
Additionally, you may notice that the roots are black and limp. And if the problem is not addressed immediately, it could lead to retarded growth and death.
How Do You Fix The Over-Fertilization Problem?
You have several options to help correct the situation and set the right salt balance. First, you can scoop the excess fertilizer from the soil. However, ensure you do not remove more than 25% of the soil from the potting mix since that could shock the plant.
Second, you can water the plant to flush out remaining fertilizers from the soil. Ensure the container has good drainage to draw the excess water; otherwise, your plant may suffer from overwatering.
You may need to repeat the watering procedure twice or thrice in the next few days to flush out all excess fertilizers from the plant roots.
After flushing the pot, avoid fertilizing your Calathea plant for one month.
4- Temperature Issues Might Cause Your Calathea Leaves To Curl And Turn Brown
Calathea leaves can turn brown when extreme temperatures- hot or cold. The leaves may develop hot spots if you place your plant near a radiator, heater, or window.
Calathea plants thrive in temperatures ranging from 65°F to 85°F (18°C to 27°C). If the temperature in your house rises above this range, the leaves may wither or shrivel.
An excessive drop in temperature can create stress for your plant, especially if they are placed near a vent or window during winter.
Excess heat increases evaporation, making the leaves lose more moisture, appear droopy, and wilt. The wilted leaves will eventually dry up, turn brown, and die.
How To Fix Calathea Temperature Problems?
The most apparent action is to move the plant away from the heat source. Ensure the potted Calathea plant is indoors or shaded to avoid scorching heat from direct sunlight.
You could hang sheer curtains at the window, thus blocking direct sunlight that can scorch the plant’s foliage.
Furthermore, you also want to ensure the soil is adequately watered, especially during hot summer, to supplement the water lost through evaporation.
Freezing temperatures may also interfere with nutrient and water absorption, causing leaves to turn brown. To prevent drafts, you can avoid this problem by ensuring your plants are away from any vent or window during cold seasons.
5- Transplanting Shock
Calathea leaves will likely wilt and turn brown when you transplant or propagate the plant to another pot.
If you transplant any plant to new soil, it undergoes shock, interfering with the roots’ ability to absorb nutrients and water, hence the yellowing or browning of the leaves.
How To Fix Or Prevent Propagation Shock
Handle the transplantation process with extra care. Ensure you do not interfere with the roots when transplanting.
Additionally, ensure you maintain the rootball moist when transplanting and continue to water thoroughly afterward.
Prune the damaged leaves and focus your attention on the growing ones. It is vital to be patient with the plant after transplantation because it takes approximately four weeks for them to recover.
6- Pest Infestation
New Calathea plants may come with pests, causing the leaves to be brown after a few weeks or purchase.
Pests like scales, mealybugs, aphids, and spider mites drain sap within the plant tissues, thus causing brown spots on the affected areas. Regularly check the underside of the plant’s leaves.
How To Fix Pest Infestation
The first step is to isolate the infected plants to prevent pests from spreading to healthy plants.
- Pluck off dead or damaged leaves from the Calathea plant using a clean, sharp knife.
- Use ready-to-spray dilute liquid of Castile soaps to kill the pest. This can be done after four to seven days until the problems are gone.
- Alternatively, you can spray neem oil every 14 days.
Calathea plant leaves turning brown is caused by underwatering, low humidity, pest infestation, and extreme temperatures.
However, you can curb and address these issues before your plants are overwhelmed. Regularly check their conditions and if you see more leaves turning yellow or brown prematurely, determine the cause and address it promptly.