Common Calathea Diseases (And How To Treat Them)

Calatheas are like the divas of the plant world. With their stunningly patterned leaves and dramatic behavior, they can be a bit finicky but oh-so-rewarding for those who love a challenge. If you're a proud plant parent to one of these beauties, you've probably noticed they can be quite sensitive to their environment and prone to a few common diseases.

In this post, we're going to explore some of the most common diseases that might afflict your Calathea and, more importantly, how you can treat them. So, grab your watering can, and let's get into the nitty-gritty of keeping your Calathea happy and healthy!

Leaf Spot Disease

One of the most common issues you'll encounter with Calatheas is leaf spot disease. It sounds pretty self-explanatory, right? This disease is characterized by brown, black, or yellow spots on the leaves. The culprits are usually fungi or bacteria, which thrive in humid environments.

Calatheas love humidity, but when it gets too high, it creates a perfect breeding ground for these pesky pathogens. This is particularly true if the foliage stays wet for too long. So, how do you tackle leaf spot disease?

• Remove Affected Leaves: Begin by pruning any leaves that show signs of infection. This will help prevent the disease from spreading to healthy parts of the plant.
• Improve Air Circulation: Ensure that your plant has good air circulation by spacing it adequately from other plants and not overcrowding it.
• Adjust Watering Habits: Avoid overhead watering. Instead, water the soil directly to keep the leaves dry.
• Use Fungicide: If the problem persists, consider using a fungicide. Make sure to follow the instructions on the label carefully to avoid damaging your plant.

By keeping these tips in mind, you should be able to get a handle on leaf spot disease and keep your Calathea looking its best.

Root Rot

Root rot is another common issue with Calatheas. It's often caused by overwatering, which leads to soggy soil and, ultimately, rotted roots. The first sign of root rot is usually yellowing leaves, but it can also cause wilting and stunted growth.

If you suspect root rot, here's what you should do:

• Check the Roots: Gently remove the plant from its pot and examine the roots. Healthy roots are white and firm, while rotted roots are brown and mushy.
• Trim Rotted Roots: Use a clean pair of scissors to cut away any rotten parts. Be sure to disinfect the scissors before and after to prevent spreading the disease.
• Repot: Repot the plant in fresh, well-draining soil. Ensure the pot has drainage holes to prevent water from accumulating at the bottom.
• Adjust Watering: Let the soil dry out a bit between waterings. Calatheas like moist soil, but they don't want to sit in water.

By keeping a close eye on your watering schedule and ensuring proper drainage, you can prevent root rot from taking over your Calathea's life.

Powdery Mildew

Powdery mildew is a fungal disease that shows up as white, powdery spots on the leaves. This can spread quickly and weaken your Calathea if not addressed promptly. It thrives in warm, dry environments, which is ironic given Calatheas' love for humidity.

To handle a case of powdery mildew:

• Remove Affected Leaves: Trim off infected leaves to stop the spread of the mildew.
• Increase Humidity: Surprisingly, increasing humidity can help. You can do this by misting the plant or using a humidifier.
• Avoid Overcrowding: Make sure there’s enough space around your plant for air to circulate.
• Use Fungicide: As a last resort, a fungicide specifically for powdery mildew can be applied. Follow the instructions to avoid harming your plant.

With these steps, your Calathea can bounce back from powdery mildew, looking fresh and lush once more.

Spider Mites

Spider mites are tiny pests that can wreak havoc on Calatheas. They're not technically a disease, but they deserve a mention because of the damage they cause. These little critters suck the sap from the leaves, resulting in speckled, discolored foliage.

Here's how you can deal with spider mites:

• Shower Your Plant: Give your Calathea a gentle shower with lukewarm water to dislodge as many mites as possible.
• Increase Humidity: Spider mites hate humidity. Keeping the air moist can help deter them.
• Use Insecticidal Soap: Spray your plant with insecticidal soap or a neem oil solution to kill any remaining mites.
• Inspect Regularly: Keep an eye on your plant for any signs of re-infestation and act quickly if you spot them.

By taking these steps, you can send spider mites packing and restore your Calathea to its former glory.

Thrips

Thrips are another pest that can cause problems for Calatheas. These tiny insects feed on plant juices and can leave your plant looking dull and damaged. They're particularly notorious for spreading quickly, so early intervention is key.

Here's how to tackle a thrips infestation:

• Isolate the Plant: Move the affected plant away from others to prevent the thrips from spreading.
• Use Sticky Traps: Place sticky traps near your plant to catch adult thrips.
• Prune Damaged Leaves: Remove any leaves that are heavily infested or damaged.
• Apply Insecticide: Use an insecticide suitable for thrips. Neem oil is a good organic option.

Regularly inspecting your plants and acting quickly at the first sign of thrips can help keep your Calathea healthy and vibrant.

Mealybugs

Mealybugs are another pest that can plague Calatheas. These small, white, cotton-like insects love to hide in the nooks and crannies of your plant. If left untreated, they can cause serious damage.

To get rid of mealybugs:

• Wipe Them Off: Use a cotton swab dipped in alcohol to remove mealybugs from the plant.
• Shower the Plant: A gentle shower can help wash away any remaining bugs and their eggs.
• Apply Neem Oil: Neem oil is effective against mealybugs. Spray the plant thoroughly, focusing on the undersides of leaves and other hiding spots.
• Regular Checks: Keep checking your plant regularly to catch any new infestations early.

With consistent care and attention, you can keep mealybugs at bay and ensure your Calathea thrives.

Environmental Stress

Calatheas can be quite sensitive to changes in their environment. Temperature fluctuations, low humidity, and drafts can all lead to stress, manifesting as leaf curling, browning, or wilting.

Here's how to reduce environmental stress:

• Stable Environment: Keep your Calathea in a spot with a consistent temperature, away from drafts and direct sunlight.
• Humidity: Maintain high humidity by misting the plant, using a pebble tray, or investing in a humidifier.
• Proper Watering: Ensure a regular watering schedule that keeps the soil consistently moist but not waterlogged.
• Leaf Care: Wipe leaves with a damp cloth to remove dust and allow the plant to breathe better.

By providing a stable and comfortable environment, your Calathea will be less prone to stress and more likely to flourish.

Nutrient Deficiency

Sometimes, the issue with your Calathea might be as simple as a lack of nutrients. Nutrient deficiencies can lead to pale leaves, slow growth, or yellowing. Providing the right balance of nutrients is crucial for the health of your plant.

To address nutrient deficiencies:

• Fertilize Regularly: Use a balanced, water-soluble fertilizer during the growing season (spring and summer) every four to six weeks.
• Check Soil pH: Ensure the soil pH is in the optimal range of 6.0 to 7.0 for nutrient uptake.
• Flush the Soil: Occasionally leach the soil by watering thoroughly to remove any salt build-up from fertilizers.
• Observe Plant Response: Monitor your plant's response to fertilization and adjust as necessary.

With the right care, your Calathea will get the nutrients it needs to grow strong and beautiful.

Final Thoughts

Calatheas may be a bit temperamental, but with the right care and attention, you can overcome these common diseases and enjoy their stunning foliage. Remember, most of these issues can be avoided with regular monitoring and a bit of preventative care.

At Cafe Planta, we’re all about helping you build a thriving plant collection. If you have any questions about your Calathea or any other plant, feel free to email us or reach out through our Instagram. We’re excited to share our passion for plants with you and help make your home a green haven.