Pocket Botanist
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Check these first
- Look closely at the underside of the leaves.
- Check the stems for sticky residue.
- Inspect the edges of the leaves for bite marks.
Likely causes
Aphids
Most likelyHow to tell: Small clusters of green or black insects on the leaf edges or stems.
What to do: Gently spray the leaves with a strong stream of water to knock the aphids off. If the infestation is heavy, use an aquatic safe insecticidal soap.
Snails
PossibleHow to tell: Small holes or ragged edges on the leaves.
What to do: Hand pick snails from the leaves in the evening. You can also place a lettuce leaf on the surface overnight to attract them for easy removal.
Find out what's wrong with your giant waterlily
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.
Scan with your phone's camera to get the app
Or go to pocketbotanist.app/get on your phone
When to worry
A few holes are normal in an outdoor pond, but you should worry if the leaves are being skeletonized or if the plant stops growing. Treat immediately if you see large colonies of aphids.
Stopping it coming back
Keep the water surface moving slightly to discourage pests and inspect your plants weekly.
Giant Waterlily: pests? Check yours with a photo
Every plant is a little different. Take a photo of your giant waterlily 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.
Scan with your phone's camera to get the app
Or go to pocketbotanist.app/get on your phone
Get the app · Or check it from a photo now, free
Questions people ask
- Can I use regular garden pesticides?
- Never use standard garden pesticides, as they are toxic to fish and other aquatic life. Always choose products labeled safe for ponds.
- Do frogs help?
- Yes, having a healthy population of frogs or fish can help keep pest populations in check naturally.
Guides to these causes
More problems with Giant Waterlily
Back to the Giant Waterlily 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.