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Spur flower · Plectranthus

Why are there white cottony bugs on my Plectranthus?

Seeing small, white, fuzzy clusters on your spur flower usually means you have mealybugs. These pests hide in the leaf axils and suck the sap from your plant. Check your plant closely for these white spots immediately.

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

Check these first

  1. Inspect the leaf axils for white cottony fluff.
  2. Check the undersides of leaves for sticky residue.
  3. Isolate the plant from your other houseplants.

Likely causes

  1. Mealybug infestation

    Most likely

    How to tell: You will see white, cottony masses in the joints where leaves meet the stem. The leaves might also look sticky or start to yellow.

    What to do: Dab the bugs with a cotton swab dipped in rubbing alcohol to kill them on contact. Follow up by spraying the entire plant with insecticidal soap every 7 days for a month.

  2. Poor air circulation

    Possible

    How to tell: Plants kept in stagnant, humid corners are more prone to pest outbreaks. If the air feels heavy around the plant, it is a prime target.

    What to do: Move your plant to a spot with better airflow. You can also use a small fan nearby on a low setting to keep the air moving.

Pests on other plants

Find out what's wrong with your spur flower

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 you see the bugs spreading to your other plants, it is time to take serious action. A few bugs are manageable, but a full infestation can weaken the plant quickly.

Stopping it coming back

Wipe down your plant leaves with a damp cloth every few weeks to remove dust and potential pests. Keep your plant healthy with proper light to help it resist attacks.

Spur flower: pests? Check yours with a photo

Every plant is a little different. Take a photo of your spur flower 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 these bugs kill my plant?
If left untreated, they will drain the plant of nutrients and cause it to decline. Catching them early makes them very easy to manage.
Can I just wash them off?
Washing helps, but mealybugs are persistent. You must use alcohol or insecticidal soap to ensure you kill the eggs and hidden adults.

Guides to these causes

More problems with Spur flower

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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.