Pocket Botanist
Check these first
- Inspect the undersides of leaves for tiny insects.
- Check if the water in the container has become stagnant or cloudy.
- Ensure the plant is not crowded by other foliage.
Likely causes
Fungal Leaf Spot
PossibleHow to tell: You will see small brown or black circular spots that may have a yellow halo around them. These often appear when the foliage stays wet for too long in cool conditions.
What to do: Remove the affected leaves immediately to stop the spread. Improve air circulation around the plant and avoid overhead watering to keep the foliage dry.
Aphid Damage
PossibleHow to tell: Small clusters of green or black insects gather on new growth and cause distorted, spotted foliage. Look closely at the stem tips for these tiny pests.
What to do: Rinse the plant gently with a steady stream of water to dislodge the aphids. If they persist, apply a mild insecticidal soap once a week until they are gone.
Find out what's wrong with your fool's watercress
The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.
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When to worry
Worry if the spots are spreading rapidly across the entire plant. A single spot on an older leaf is usually just part of the natural aging process.
Stopping it coming back
Keep the water fresh by changing it regularly and ensure the plant has plenty of space for air to move around it.
Fool's watercress: spots? Check yours with a photo
Every plant is a little different. Take a photo of your fool's watercress and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.
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Questions people ask
- Can I use fungicide on my watercress?
- It is best to avoid chemical fungicides since this is an edible plant. Stick to physical removal of damaged leaves and better air flow.
- Are these spots harmful to me?
- The spots themselves are usually fungal and not toxic, but you should not eat leaves that show signs of decay or mold.
Guides to these causes
More problems with Fool's watercress
Back to the Fool's watercress guide
This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.