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New Zealand Flax · Phormium tenax

Why are there white cottony spots on my New Zealand Flax?

You are likely dealing with mealybugs, which love to hide deep in the base of your flax leaves. Check the tight crevices where the leaves meet the center of the plant first.

Check these first

  1. Inspect the base of the leaves for white cottony fluff.
  2. Check for sticky residue on the foliage.
  3. Look for tiny crawling insects near the soil line.

Likely causes

  1. Mealybug infestation

    Most likely

    How to tell: Look for small, white, fuzzy masses that look like bits of cotton tucked into the leaf folds. You might also see a sticky residue called honeydew on the leaves.

    What to do: Wipe the visible bugs away with a cotton swab dipped in rubbing alcohol. Spray the entire plant with insecticidal soap or neem oil every 7 days until they are gone.

  2. Poor air circulation

    Possible

    How to tell: Stagnant air creates a perfect environment for pests to multiply quickly. If your plant is crowded by other pots, it is more prone to these visitors.

    What to do: Move your plant to a spot with better airflow. Space it out from other plants to help the foliage dry properly.

When to worry

If the infestation covers the entire plant and the leaves start to yellow or wilt, it is a serious problem. A few bugs are easy to manage, but a full colony can weaken the plant significantly.

Stopping it coming back

Keep your plant in a well ventilated area and inspect the leaf bases every time you water.

Not sure which one it is? Photograph your new zealand flax.

This page lists the usual causes. Pocket Botanist looks at your actual leaf 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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Questions people ask

Can I just wash the bugs off with water?
Water alone will not kill them. You need to use alcohol or insecticidal soap to break down their protective coating.
Will these bugs spread to my other plants?
Yes, mealybugs move easily between plants. Isolate your flax immediately until you are sure the pests are gone.

More problems with New Zealand Flax

Back to the New Zealand Flax guide

This article was generated with AI from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.