Aphid control in tulip poplar tree - Ask Extension
There is a 4-story high tulip poplar tree in the yard that looks great every spring, then gets infested with aphids so that it starts losing leaves in...
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Aphid control in tulip poplar tree #925818
Asked March 10, 2026, 11:02 PM EDT
There is a 4-story high tulip poplar tree in the yard that looks great every spring, then gets infested with aphids so that it starts losing leaves in July and through the fall. I have tried ladybugs but the tree is just too high for good coverage. Tried a systemic treatment a few years ago and it seemed to help some. It's actually 2 trees kind of sharing the trunk base.
Clatsop County Oregon
Expert Response
Thanks for your question.
Oregon State's landscape plants information concurs that aphids can be a serious problem - https://landscapeplants.oregonstate.edu/plants/liriodendron-tulipifera
In dealing with aphids, keeping your tree healthy and not water-stressed is the best defense and will help provide a good environment for beneficial predators like lacewings, lady beetles, parasitic wasps.
You can also try blasting the aphids off the tree with a strong stream of water. If they are dislodged, they may not be able to return. Check your tree early and try to blast them off before leaves start to curl.
Check to see if you have ants climbing the tree. Ants are known to tend aphids and feed off the honeydew the aphids produce. Ants will protect the aphids from insect predators also. To prevent ants from climbing the tree you can wrap it with a sticky wrap like Tanglefoot.
If you want to try chemical control, always follow label instructions. You might consider using insecticidal soap or horticultural oil which are less toxic to beneficial insect predators. If you use a systemic chemical control it can be deadly to beneficial insects like bees and other pollinators so it should not be applied when flowers are in pre-bloom or bloom.
Oregon State's landscape plants information concurs that aphids can be a serious problem - https://landscapeplants.oregonstate.edu/plants/liriodendron-tulipifera
In dealing with aphids, keeping your tree healthy and not water-stressed is the best defense and will help provide a good environment for beneficial predators like lacewings, lady beetles, parasitic wasps.
You can also try blasting the aphids off the tree with a strong stream of water. If they are dislodged, they may not be able to return. Check your tree early and try to blast them off before leaves start to curl.
Check to see if you have ants climbing the tree. Ants are known to tend aphids and feed off the honeydew the aphids produce. Ants will protect the aphids from insect predators also. To prevent ants from climbing the tree you can wrap it with a sticky wrap like Tanglefoot.
If you want to try chemical control, always follow label instructions. You might consider using insecticidal soap or horticultural oil which are less toxic to beneficial insect predators. If you use a systemic chemical control it can be deadly to beneficial insects like bees and other pollinators so it should not be applied when flowers are in pre-bloom or bloom.
Thank you for your advice and suggestions. Due to the size of the tree(s), there are limitations on some methods. It is not possible to spray off the aphids, tree is 2 times the height of the 2-story house. It surely is beautiful before it gets the bugs on it!
I hope to find a suitable systemic treatment to at least reduce the infestation this summer.
Thank you,
Sincerely, Ellen
You're welcome. From your photos, I can see the difficulty involved with any spray effort.. Your trees seem to be in good shape now.
