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Bottlebrush · Callistemon

Why are there bumps on my Bottlebrush stems?

Those bumps are likely scale insects, which feed on your plant's sap. Check the undersides of leaves and along the stems for small, waxy, or brown raised spots.

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

Check these first

  1. Inspect the stems for small, raised bumps that can be scraped off.
  2. Look for sticky honeydew on the leaves below the stems.
  3. Check for ants, as they often farm scale insects.

Likely causes

  1. Scale insects

    Most likely

    How to tell: You will see small, immobile brown or tan bumps clinging to the stems or leaf veins. They often leave behind a sticky residue called honeydew.

    What to do: Scrape off light infestations with your fingernail or a soft brush. For larger issues, spray the entire plant with horticultural oil or neem oil every 7 to 10 days until the pests are gone.

  2. Aphids

    Possible

    How to tell: These are tiny, soft bodied insects that cluster on new, tender growth. They cause leaves to look distorted or sticky.

    What to do: Blast the insects off with a strong stream of water from your hose. If they persist, apply insecticidal soap directly to the affected areas.

Pests on other plants

Find out what's wrong with your bottlebrush

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

If the plant starts losing vigor or the leaves turn yellow, the infestation is severe. A few bumps are manageable, but a total coating of stems requires immediate treatment.

Stopping it coming back

Keep your Bottlebrush healthy with proper sun and water, as stressed plants are more attractive to pests. Check the stems regularly during your routine watering.

Bottlebrush: pests? Check yours with a photo

Every plant is a little different. Take a photo of your bottlebrush 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 just wash them off?
Yes, for minor cases, a firm spray of water can dislodge many insects. However, you must follow up with oil if they return.
Will these pests kill my plant?
A heavy infestation can weaken the plant significantly over time. Treat it early to prevent stunted growth and leaf drop.

Guides to these causes

More problems with Bottlebrush

Back to the Bottlebrush 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.