Few plants rank higher on the “easy houseplant” list than the aglaonema. An herbaceous perennial native to the tropical forest floors of Asia, it is adapted to filtered sunlight — at home, it tolerates some of our shadiest, low light rooms.
Aglaonemas, also known as Chinese evergreens, are a popular houseplant known for their lush green leaves and easy care requirements. However, even hardy plants like aglaonemas can fall victim to diseases that impact their health and appearance. By learning to identify the most common aglaonema diseases and employing proper treatment methods, you can keep your plants thriving.
Understanding Common Aglaonema Diseases
Several diseases may affect an aglaonema plant, ranging from fungal and bacterial infections to pest infestations. The most prevalent include
Leaf Spot
Leaf spot manifests as dark, irregular spots scattered across the leaves It is caused by a fungal infection. Left untreated, leaf spot can cause significant leaf loss
Root Rot
Root rot also stems from a fungal infection. It attacks the roots, causing them to appear brown, slimy, or shriveled. Above ground, symptoms include wilting, yellowing leaves, and stunted growth.
Bacterial Blight
Bacterial blight leads to water-soaked lesions on the leaves, typically surrounded by a yellow halo. The lesions eventually turn brown or black. Severe infections can make leaves curl up and drop off entirely.
Mealybugs
Mealybugs are small, soft-bodied insects that attach themselves to the stems and leaves. They secrete a sticky substance called honeydew. Too many mealybugs will weaken and even kill a plant.
Spider Mites
Spider mites are tiny pests that suck nutrients from the leaves. They leave behind yellow stippled patterns as they feed. An infestation can slow growth and reduce vigor.
Effectively Identifying Aglaonema Diseases
The first step in treating any plant problem is to properly identify the cause. Here are tips for accurately diagnosing common aglaonema diseases:
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Check the leaves for spots, lesions, sticky residue, web-like threads, and insects or bugs. Compare these signs to disease descriptions.
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Look at the roots. Are they brown, slimy, or shriveled? This indicates root rot.
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Assess the overall condition of the plant. Wilting, yellowing, curled leaves, and stunted growth all point to an underlying issue.
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Consider environmental factors. Overwatering and insufficient light often contribute to disease.
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Examine other nearby plants. Spread of disease may suggest a highly contagious pathogen.
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Send photos of the symptoms to your local agricultural extension office if you need help reaching a diagnosis.
Treating Diseased Aglaonemas
Once you’ve identified the problem plaguing your aglaonema, you can take steps to treat it:
Fungal Diseases
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Improve air circulation and reduce humidity to discourage fungal growth.
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Remove and destroy all visibly diseased plant material. Sterilize shears between cuts.
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Repot in fresh, sterile potting mix to eliminate pathogens in the soil.
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Apply a fungicide like neem oil according to package directions.
Bacterial Infections
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Prune off infected leaves and isolate the plant from others.
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Apply a copper-based bactericide to protect healthy tissue.
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Reduce watering frequency and avoid wetting the leaves.
Pest Infestations
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Dislodge pests with a strong spray of water or wipe them away manually.
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Apply insecticidal soap or horticultural oil to suffocate insects.
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Introduce predator insects like ladybugs to naturally control pests.
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Use yellow sticky traps to monitor and capture adult insects.
No matter the disease or other problem, be sure to properly dispose of all discarded plant material to prevent further contamination. With prompt treatment, even a diseased aglaonema can make a full recovery.
Answering Common Questions on Aglaonema Diseases
Caring for ailing plants often raises additional questions. Here are answers to some frequently asked questions on managing diseases in aglaonema:
How can I prevent diseases in my aglaonema?
The best prevention is cultural control through proper plant care. Provide optimal lighting, moderate temperatures, well-draining soil, and appropriate watering and fertilization. Also monitor for pests and treat early. Disinfect tools between uses.
What causes leaf spot in aglaonema?
Leaf spot is caused by a fungal pathogen. Wet foliage, high humidity, and crowded conditions promote development of the disease.
Why is my aglaonema drooping and wilting?
Wilting and drooping leaves suggest the plant is dehydrated. But if the soil is moist, the cause is more likely a root system damaged by root rot. Other possible factors are overwatering, high temperatures, or dry air.
Should I cut off infected aglaonema leaves?
Removing infected leaves can slow disease progression. But be sure to sterilize pruners before each cut to avoid spreading the pathogen. Properly discard all plant debris after pruning.
How often should I treat a diseased aglaonema plant?
Follow all label instructions for treatment frequency. For mild infections, one or two applications may suffice. More aggressive diseases need applications every 7-14 days until the problem resolves.
When should I repot or replace my aglaonema?
Repotting is advisable when treating root rot or other soil-borne diseases. It eliminates pathogens and provides fresh growing medium. Otherwise repot every 2-3 years as the plant outgrows its container.
Keeping Your Aglaonemas Healthy
While aglaonema diseases require swift treatment when they occur, prevention is the best approach. Provide good care tailored to your plant’s needs, and monitor frequently for any signs of distress. Know which diseases are most likely to occur and how to identify them. With proper knowledge and management, you can help your aglaonemas live long, healthy, and disease-free lives.
Q: Why are the leaves of my aglaonema turning yellow?
A: Yellow leaves can indicate overwatering, poor drainage, or a nutrient deficiency. Adjust your watering routine so the top of the soil has time to dry, and ensure the pot has good drainage.
How To Care For Aglaonemas
Water your Aglaonema when the top 1-2 inches of soil feels dry. They prefer the soil to be slightly moist, but not waterlogged. Overwatering can lead to root rot.
Use a balanced, water-soluble houseplant fertilizer diluted to half-strength, applied every month during the growing season (spring and summer). Reduce fertilization in fall and winter.
Pruning is not typically necessary, but you can trim away any yellow or damaged leaves to keep the plant looking tidy. Use clean, sharp scissors for pruning.
Repot aglaonemas every 1-3 years or when they become rootbound. Spring or early summer is the best time to repot. Choose a pot that’s slightly larger than the current one and has good drainage.
Aglaonemas can be easily propagated by division during repotting. Carefully separate the stems, ensuring each new plant has an adequate root system, and pot them separately.