Common Calla Lily Diseases (And How To Treat Them)

Calla lilies are stunning, aren’t they? With their elegant blooms and rich history, they’ve captured the hearts of countless plant lovers. Yet, like any cherished plant, they aren’t immune to the odd hiccup now and then. Whether it’s a suspicious spot or a wilting leaf, knowing what might be ailing your calla lily can make all the difference in keeping it thriving.

In this article, we’ll chat about some common diseases that can affect calla lilies and, more importantly, how you can treat them. From fungal infections to bacterial issues, we’ll cover a range of topics to arm you with the knowledge you need to care for your beloved plants.

Fungal Leaf Spot

Fungal leaf spot is like a pesky guest that just won’t leave. If you’ve noticed small, round spots on your calla lily leaves, you might be dealing with this common problem. The spots can vary in color, but they often start out as tiny, water-soaked areas before turning brown or black.

So, what causes it? Moisture is usually the main culprit. When leaves remain wet for extended periods, it creates a perfect environment for fungal spores to thrive. Humid conditions, poor air circulation, and overwatering are all contributing factors.

To tackle fungal leaf spot, start by trimming away affected leaves. This helps prevent the spread of spores to healthy parts of the plant. Ensure your calla lilies have good air circulation by spacing them well and not crowding them with other plants. Water them at the base rather than overhead, and try to do it in the morning so any splashes dry up quickly.

In more severe cases, you might consider using a fungicide. There are plenty of options out there, so pick one that’s safe for ornamental plants. Just follow the instructions on the label, and remember that prevention is always better than cure!

Root Rot

Root rot is like a villain lurking beneath the surface, often unnoticed until it’s too late. It’s primarily caused by overwatering, which leads to soggy soil and suffocated roots. Fungi like Pythium and Phytophthora love these conditions and will quickly set up shop, causing the roots to rot.

If your calla lily is wilting despite your best efforts, or if the leaves are yellowing, you might want to check the roots. Healthy roots are firm and white, but if they’re brown and mushy, root rot is likely the problem.

To save your plant, you’ll need to act fast. Carefully remove the plant from its pot and inspect the roots. Trim away any that are brown and slimy, then repot the plant in fresh, well-draining soil. Make sure the new pot has drainage holes, and avoid using a saucer that holds water.

To prevent future occurrences, adjust your watering habits. Allow the soil to dry out slightly between waterings. It’s a classic case of “less is more” when it comes to water.

Bacterial Soft Rot

Next up is bacterial soft rot, which sounds as unpleasant as it is. This disease affects the rhizomes and stems, causing them to become soft and mushy. It usually starts at the base and works its way up, leaving a trail of destruction in its wake.

Soft rot is typically caused by bacteria that thrive in warm, wet conditions. If your calla lilies are planted too deep or if water pools around the base, your plants are at risk. You might notice a foul odor, which is a clear sign something’s amiss.

Unfortunately, bacterial soft rot is difficult to treat once it sets in. Your best bet is to remove and destroy infected plants to prevent the spread to healthy ones. If you catch it early, you might be able to save the plant by cutting away the affected areas and improving drainage.

As always, prevention is key. Ensure your calla lilies are planted at the correct depth, and avoid overwatering. Also, practice good garden hygiene by cleaning your tools between uses to avoid spreading bacteria.

Powdery Mildew

Powdery mildew is a classic garden nuisance. If you notice a white, powdery substance on your calla lily leaves, you’re likely dealing with this fungal infection. It might look like someone sprinkled flour on your plant, but it’s actually a sign of a fungal spore party.

This disease thrives in dry conditions with high humidity, making it a common issue in climates with warm days and cool nights. It can slow down your plant’s growth and make the leaves look unsightly.

To treat powdery mildew, start by removing affected leaves. This helps reduce the number of spores that can spread to other plants. Improve air circulation around your calla lilies and ensure they’re getting plenty of sunlight.

For a more natural remedy, you can try making a homemade spray. Mix water with a bit of baking soda or apple cider vinegar and spray it on the affected areas. If the problem persists, you might need to turn to a fungicide. Just make sure it’s safe for use on ornamental plants.

Anthracnose

Anthracnose is a less common but still noteworthy disease that can affect calla lilies. It’s caused by fungi that thrive in wet, humid conditions and can result in leaf spots, stem lesions, and even flower blight.

You might spot small, dark lesions on leaves and stems, often with a sunken appearance. If left unchecked, these can merge to form larger areas of damage, ultimately weakening your plant.

The best way to manage anthracnose is to keep your plants dry. Avoid overhead watering, and ensure good air circulation around your plants. If you notice any infected leaves or stems, remove them promptly.

In severe cases, a fungicide may be necessary. Look for one labeled for use on anthracnose and follow the instructions carefully. Remember to treat not only the affected plant but also any nearby plants that could be at risk.

Botrytis Blight

Botrytis blight, often referred to as gray mold, is another fungal issue that calla lilies can face. It loves cool, damp conditions and can affect leaves, stems, and flowers, causing them to develop a fuzzy gray mold.

Symptoms include brown spots on leaves and flowers, which eventually become covered in gray mold. If your calla lilies are planted too close together or if they’re in a poorly ventilated area, they’re at a greater risk of developing botrytis blight.

To manage it, start by removing and disposing of any affected parts of the plant. Improve air circulation and avoid overhead watering. If necessary, a fungicide can help control the spread of the disease.

Preventing botrytis blight involves keeping your plants healthy and stress-free. Ensure they’re planted in well-draining soil, and avoid overcrowding to promote good air circulation.

Calla Lily Virus

Viruses can also be a threat to calla lilies, with symptoms ranging from leaf mottling to stunted growth. Unfortunately, viral infections are incurable, and affected plants will need to be removed to prevent spreading the virus to healthy ones.

Viruses are often spread by pests like aphids, so keeping these critters in check is an important preventative measure. Regularly inspect your plants for signs of pest activity, and use insecticidal soap or neem oil to control any infestations.

Practice good garden hygiene by cleaning your tools and avoiding working with plants when they’re wet. This minimizes the risk of spreading viruses from plant to plant.

Rust

Rust is a fungal disease that can cause orange or rust-colored pustules to form on the undersides of leaves. While it might sound like a problem for old cars rather than plants, it’s a concern for calla lily owners.

This disease thrives in damp conditions and can spread quickly if not managed. Affected leaves may yellow and drop, weakening the plant over time.

To treat rust, remove and dispose of any infected leaves. Improve air circulation and avoid overhead watering. If necessary, a fungicide can help control the spread of the disease.

Preventing rust involves keeping your plants healthy and stress-free. Ensure they’re planted in well-draining soil, and avoid overcrowding to promote good air circulation.

Final Thoughts

Caring for calla lilies means being vigilant about their health and ready to tackle any issues that arise. From fungal leaf spots to root rot, understanding what might be ailing your plant and how to address it is key to keeping your calla lilies in top shape.

At Cafe Planta, we’re all about helping you nurture your plant family. If you have questions or need advice, feel free to email us or send a DM on Instagram. Whether you’re a seasoned plant parent or new to the green scene, we’re here to support you on your plant journey.