Pocket BotanistCheck these first
- Look for sticky residue on the leaves.
- Examine the undersides of leaves for clusters of insects.
- Check for ants crawling up the trunk.
Likely causes
Aphids
Most likelyHow to tell: You will see sticky honeydew on the leaves and small green or black insects clustered on new growth. Ants are often present as they farm the aphids.
What to do: Spray the leaves with a strong stream of water to knock the aphids off. If the infestation is heavy, use insecticidal soap once a week.
Scale Insects
PossibleHow to tell: Small, bump like growths appear on the twigs and branches. They look like tiny shells stuck to the bark.
What to do: Scrub the scales off with a soft brush or apply horticultural oil during the dormant season.
When to worry
A few aphids are rarely a threat to a mature tree. Worry only if the leaves start curling or if the tree shows signs of severe stress.
Stopping it coming back
Encourage beneficial insects like ladybugs to visit your garden, as they eat aphids naturally.
Not sure which one it is? Photograph your bigleaf maple.
This page lists the usual causes. Pocket Botanist looks at your actual leaf and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.
Questions people ask
- Is the sticky stuff on my leaves harmful?
- The honeydew itself is harmless, but it can lead to sooty mold growth on the leaves.
- Should I use heavy pesticides?
- Avoid strong chemicals as they kill the beneficial insects that help control the aphid population.
More problems with Bigleaf Maple
Back to the Bigleaf Maple guide
This article was generated with AI from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.