Crassula mesembrianthoides subsp. hispida White Cottony Spots - Causes & Fixes

Jump to cause: Mealybugs Powdery Mildew Sclerotinia (White Mold)

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Mealybugs

These small, sap-sucking insects produce a white, waxy, cottony secretion to protect themselves. They often cluster in the crevices of the Hairy Crassula's leaves and stems, feeding on plant juices and weakening the succulent.

Very Common

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How to confirm: Use a toothpick to gently probe the white spots; if they move or reveal small insects underneath, it is 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 to kill the insects and their waxy coatings.

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

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Powdery Mildew

This fungal disease presents as white, flour-like patches on the leaf surfaces. In succulents like Crassula, high humidity and poor airflow can trigger spore germination on the plant's foliage.

Common

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How to confirm: Check if the white spots can be wiped away easily with a damp cloth, leaving a clean surface underneath.

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1 Apply an organic fungicide to eliminate existing fungal spores and prevent further spread across the foliage.

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 levels to create an environment less conducive to mildew growth.

3 Prune and discard any heavily infected leaves to prevent the disease from spreading to healthy parts of the Crassula.

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Sclerotinia (White Mold)

Certain fungal pathogens can cause white, fuzzy mycelium to grow on the stem or base of the plant, especially if the substrate remains too damp for this xeric species.

Common

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How to confirm: Inspect the base of the plant for any signs of softening or mushy tissue accompanied by the white fuzz.

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1 Immediately remove any heavily infected stems or plant parts to prevent the fungus from spreading to the rest of the plant.

2 Reduce watering frequency and ensure the substrate is completely dry before the next application; use a moisture meter to monitor the soil depth.