Pachyphytum oviferum White Cottony Spots - Causes & Fixes

Jump to cause: Mealybugs Powdery Mildew Cottony Blight (Botrytis)

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Mealybugs

These small, sap-sucking insects produce a white, waxy, cottony secretion to protect themselves while feeding on the Moonstone's fleshy leaves. They often cluster in the crevices between the leaves and near the base of the plant.

Very Common

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How to confirm: Use a cotton swab dipped in rubbing alcohol to dab the spots; if they dissolve instantly, it is likely mealybugs.

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1 Isolate the plant immediately to prevent the mealybugs from spreading to your other houseplants.

2 Treat the infestation by spraying the plant with an organic insecticide or neem oil to kill the insects and their waxy coating.

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3 Use a cotton swab dipped in isopropyl alcohol to manually remove visible white cottony clusters from the crevices of the leaves.

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Powdery Mildew

This fungal pathogen manifests as a white, dusty coating on the leaf surfaces, often appearing when there is high humidity and poor airflow around the succulent. Unlike insects, this looks more like a fine flour dust than distinct cottony clumps.

Common

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How to confirm: Check if the white substance can be easily rubbed off with your finger and if it appears as a thin film rather than raised clusters.

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1 Treat the affected leaves immediately with an organic fungicide to stop the spread of the fungal spores.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Improve air circulation around the plant and reduce humidity by avoiding overhead watering, which helps prevent future mildew outbreaks.

3 Ensure the plant is in a well-draining medium with added aeration to keep the base of the plant dry.

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Cottony Blight (Botrytis)

In conditions of excessive moisture, Botrytis can cause soft, decaying tissue covered in a greyish-white fungal mass. This usually affects the plant if the Moonstone's leaves remain damp for extended periods.

Common

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How to confirm: Inspect the area under the white spots to see if the leaf tissue feels mushy or has turned translucent/brown.

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1 Immediately remove and discard any leaves showing soft, decaying tissue or white fungal mass to prevent the spread of the blight.

2 Improve air circulation around the plant and reduce watering frequency to ensure the leaves do not remain damp for extended periods.