Kalanchoe marnieriana White Cottony Spots - Causes & Fixes

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

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Mealybugs

These small insects secrete a white, waxy, cottony substance to protect themselves while feeding on the sap of Kalanchoe leaves and stems. They often cluster in the crevices between fleshy leaves where moisture collects.

Very Common

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

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1 Isolate the plant immediately from other greenery 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 remove the waxy coating.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

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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 and stems.

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Powdery Mildew

A fungal disease that manifests as white, flour-like patches on the leaf surface. In Kalanchoe, this is often triggered by high humidity combined with poor air circulation around the succulent foliage.

Common

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How to confirm: Check if the white spots can be rubbed off easily and if the leaf tissue underneath appears slightly yellowed or necrotic.

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

Bonide Captain Jack's Copper Fungicide 32 oz

0.9 L • 1 pcs • Organic

$12

In Stock

2 Improve air circulation around the plant and reduce humidity by avoiding overhead watering and ensuring the foliage can dry quickly.

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

Fiskars 5/8" Bypass Pruning Shears

Cutting Tools

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Cottony Blight (Botrytis)

While less common in succulents, high moisture levels on fleshy leaves can lead to fungal rot that presents as fuzzy, greyish-white patches. This typically affects the plant during periods of excessive humidity or improper drainage.

Common

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How to confirm: Inspect the base of the spots for any signs of softening or mushy, dark tissue on the leaf stem.

build How to fix it

shopping_cart Recommended Products

1 Prune away any leaves or stems showing fuzzy white patches using sterilized shears to prevent the fungus from spreading to healthy tissue.

Fiskars 5/8" Bypass Pruning Shears

Cutting Tools

$13

In Stock

2 Apply an organic fungicide to the affected area and surrounding foliage to control the spread of the blight.

Bonide Captain Jack's Copper Fungicide 32 oz