Portulaca molokiniensis 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, cotton-like substance to protect themselves while feeding on the succulent stems and leaves of Portulaca molokiniensis. Their feeding can lead to yellowing or stunted growth in this species.

Very Common

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How to confirm: Use a cotton swab dipped in isopropyl alcohol to dab the spots; if they dissolve and reveal small insects, it is mealybugs.

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1 Isolate the plant immediately to prevent the mealybugs from spreading to your other succulents and 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

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

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Powdery Mildew

This fungal pathogen manifests as a white, flour-like coating on the surface of the leaves, often triggered by high humidity and poor air circulation around the dense succulent foliage. It can eventually cause the leaves to shrivel or drop.

Common

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How to confirm: Check if the white spots look like dust that can be wiped off easily and if they appear primarily on the leaf surfaces.

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1 Apply an organic fungicide to eliminate the existing fungal spores and prevent the spread to healthy 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 by avoiding overhead watering on the leaves.

3 Prune and discard any heavily infected leaves to reduce the pathogen load in the plant's environment.

Fiskars 5/8" Bypass Pruning Shears

Cutting Tools

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Cottony Blight (Botrytis)

In high-moisture environments, Botrytis can cause fuzzy, gray-to-white fungal growth, particularly around the base of the leaves or decaying organic matter in the soil.

Common

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How to confirm: Inspect if the white spots are accompanied by soft, decaying tissue or browning on the succulent stems.

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1 Remove all infected plant material and decaying organic matter from the soil surface to prevent the fungus from spreading.

2 Apply an organic fungicide to treat the remaining healthy tissue and protect against further fungal development.