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Bigleaf Hydrangea · Hydrangea

What are the bugs on my bigleaf hydrangea?

Aphids are common visitors on new hydrangea growth, appearing as small clusters of insects. Check the undersides of leaves and new stems to identify these pests.

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

Check these first

  1. Inspect the undersides of the leaves.
  2. Look for sticky residue on the foliage.
  3. Check for white dusty patches on the leaves.

Likely causes

  1. Aphids

    Most likely

    How to tell: You see tiny green or black insects clustering on new growth and sticky residue on leaves.

    What to do: Spray the aphids off with a strong stream of water from your hose. For heavy infestations, use insecticidal soap once a week.

  2. Powdery mildew

    Possible

    How to tell: A white, dusty fungal growth appears on the surface of the leaves.

    What to do: Improve air circulation by thinning out crowded branches. Apply a fungicide if the infection is widespread.

Pests on other plants

Find out what's wrong with your bigleaf hydrangea

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

A few aphids are usually not a problem. Worry if the leaves start to curl or turn yellow from the pest damage.

Stopping it coming back

Keep the plant healthy with proper water and light. Avoid overhead watering to prevent fungal issues.

Bigleaf Hydrangea: pests? Check yours with a photo

Every plant is a little different. Take a photo of your bigleaf hydrangea 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

Will aphids kill my hydrangea?
Usually not, but they can weaken the plant. It is best to wash them off as soon as you see them.
Is the white dust on my leaves a pest?
That is powdery mildew, which is a fungus. It thrives in humid conditions with poor airflow.

Guides to these causes

More problems with Bigleaf Hydrangea

Back to the Bigleaf Hydrangea 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.