Kalanchoe Rosalina Don Sergio White Cottony Spots - Causes & Fixes

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

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Mealybugs

These small, sap-sucking insects produce a white, waxy, cotton-like secretion to protect themselves. In Kalanchoe species, they often cluster in the crevices between leaf nodes and near the base of the succulent stems.

Very Common

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How to confirm: Use a cotton swab dipped in rubbing alcohol to dab the white spots; if they dissolve and turn brown, 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 coatings.

Bonide Captain Jack's Neem Oil 32 oz

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3 Use a cotton swab dipped in isopropyl alcohol to manually remove visible white cottony clusters from the leaf crevices and stem bases.

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Powdery Mildew

This fungal pathogen manifests as a white, dusty coating on the leaf surfaces. It thrives in Kalanchoe plants kept in environments with high humidity and poor air circulation.

Common

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How to confirm: Check if the white spots can be easily wiped off with your finger like dust or flour.

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1 Apply an organic fungicide to the affected leaves to eliminate the powdery mildew spores and prevent further spread.

Bonide Captain Jack's Copper Fungicide 32 oz

0.9 L • 1 pcs • Organic

$12

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2 Improve air circulation around the plant and reduce humidity by avoiding overhead watering and ensuring the plant is not crowded.

3 Prune and dispose of any heavily infected leaves to prevent the fungus from spreading to healthy foliage.

Fiskars 5/8" Bypass Pruning Shears

Cutting Tools

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Cottony Blight (Sclerotinia)

While less common in succulents, certain fungal pathogens can cause white, fuzzy mycelium to appear on decaying plant tissue. This usually occurs if the Kalanchoe stems are staying too wet.

Common

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How to confirm: Inspect the base of the plant for any softened, darkened, or mushy stem tissue underneath the white fuzz.

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1 Prune away all affected stems and decaying plant tissue using sterilized shears to prevent the fungal spread.

Fiskars 5/8" Bypass Pruning Shears

Cutting Tools

$13

In Stock

2 Apply a fungicide to the remaining healthy tissue to combat the Sclerotinia pathogen.

Bonide Captain Jack's Copper Fungicide 32 oz