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Cottonwood · Populus

How do I know if my poplar has borers?

Poplar borers are serious pests that tunnel into the trunk and weaken the wood. You might notice sawdust at the base of the tree or small holes in the bark. Check the trunk closely for signs of entry.

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pests on a plant
Photo: Jules Verne Times Two, CC BY-SA 4.0

Check these first

  1. Look for sawdust or frass at the base of the trunk.
  2. Examine the bark for small, circular exit holes.
  3. Check for sticky residue on the leaves.

Likely causes

  1. Poplar Borer Larvae

    Most likely

    How to tell: Look for small holes in the bark and piles of wood shavings or frass at the base of the tree.

    What to do: If the infestation is small, you can sometimes probe the holes with a wire to kill the larvae. For larger infestations, consult a professional arborist about systemic insecticide treatments.

  2. Aphids

    Possible

    How to tell: Leaves may look curled or sticky from honeydew secretions.

    What to do: Spray the leaves with a strong stream of water to knock them off. If they persist, use insecticidal soap once a week until they are gone.

Pests on other plants

Find out what's wrong with your cottonwood

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

Borers are a major concern because they compromise the tree's structural integrity and can lead to branch failure.

Stopping it coming back

Keep your tree healthy with proper watering and avoid wounding the bark with lawn equipment.

Cottonwood: pests? Check yours with a photo

Every plant is a little different. Take a photo of your cottonwood 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 save a tree with borers?
Yes, if caught early, but heavy infestations often require professional help.
Do borers attack healthy trees?
They prefer stressed or damaged trees, so keeping your poplar vigorous is the best defense.

Guides to these causes

More problems with Cottonwood

Back to the Cottonwood 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.