Leaf rot in houseplants
Leaf rot is a plant disease that can be caused by various fungi or bacteria and usually results in dark, rotting spots on the leaves. It occurs particularly in humid, warm weather and can affect many plant species, including houseplants. Houseplants such as orchids, anthuriums , and monsteras are frequently affected by leaf rot.
What does leaf rot look like?
Early signs
- Small, watery-looking spots
- Soft, moist fabric
- It usually starts on the lower leaves
- Stains quickly become darker.
- Slight sheen on the leaf surface
Progressive infestation
- The spots turn dark brown to black and get larger.
- Discolored dark leaf edges
- The affected tissue is mushy or slimy.
- Leaves may curl downwards, hang limply, or fall off.
- Possibly greyish-white fungal growth or downy mold.
Severe infestation
- Entire leaves rot or disintegrate upon contact.
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Musty or rotten smell
- Rot spreads to stems, leaf stalks, or fruits.
- Plant overall looks wilted, rotten or burned
Leaf rot vs. leaf spot disease: Is there a difference?
Leaf rot and leaf spot disease sound very similar, but do not describe exactly the same thing, even though they are similar in symptoms and can easily be confused.
Leaf spot disease typically presents as small, well-defined spots on the leaves. These spots are brown, black, or yellowish and sometimes have a light-colored border. As the disease progresses, these spots dry out. The leaves may fall off prematurely, but usually do not rot completely.
Leaf rot also manifests itself through brown spots. However, the key difference is that the leaf tissue becomes soft, mushy, and dark. It literally rots. Leaf rot spreads quickly, often affects stems and fruits, and can destroy entire plants.
Causes of leaf rot
If the leaves of your houseplant start to rot, there can be several reasons. If water accumulates in the saucer and the roots are constantly wet, they will begin to rot, weakening the plant. Overly frequent misting of the leaves also encourages the spread of fungi and bacteria. Poor air circulation, caused by plants being placed too close together or a lack of airflow, further promotes moisture and thus rot. Additionally, unclean tools, such as contaminated scissors or knives, can transmit pathogens to other plants when pruning.
Treat leaf rot
- Remove affected leaves immediately and cut back to healthy tissue.
- Improve air circulation and temporarily isolate the plant.
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Check and adjust watering practices and drainage.
- In severe cases, use a suitable fungicide or bactericidal agent.
Care and prevention after treatment
To prevent leaf rot from recurring, the plant should be placed in a well-ventilated location and waterlogging should be strictly avoided. Use fresh, well-draining soil and ensure clean pots to prevent relapses. Water less frequently and only when the top layer of soil is dry. Also, make sure that moisture doesn't remain on the leaves for extended periods and use clean tools when pruning or repotting.
When is the plant beyond saving?
If leaf rot has progressed to the point where stems, roots, and leaves are completely rotten, the plant is usually beyond saving. It will appear soft and watery and have a distinctly rotten or musty odor. In this state, the pathogen can continue to spread and infect other plants. Therefore, the affected plant, along with the soil and pot, should be thoroughly disposed of, and the surrounding area cleaned afterward to prevent reinfection.
