Crassula nudicaulis herrei 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 as they feed on the succulent's stems and leaf axils. In Crassula species, they often congregate in the crevices where leaves meet the stem.

Very Common

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How to confirm: Use a cotton swab dipped in rubbing alcohol to dab the 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 Use a cotton swab dipped in isopropyl alcohol to manually remove the visible white cottony masses from the leaf axils and stems.

3 Apply an organic insecticide spray to the entire plant, ensuring you reach the crevices where pests hide, to eliminate remaining insects and eggs.

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Powdery Mildew

A fungal pathogen that manifests as white, flour-like patches on the surface of the leaves. This typically occurs in Crassula nudicaulis herrei when there is high humidity combined with poor air circulation.

Common

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How to confirm: Check if the white spots can be wiped off easily and if new growth appears stunted or distorted.

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1 Apply an organic fungicide to eliminate the existing fungal patches and prevent further spread of the mildew.

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 hospitable to fungal pathogens.

3 Prune and discard any heavily infected leaves to prevent the spores from contaminating the rest of the plant.

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Cottony Blight (Botrytis)

This fungal pathogen thrives in overly damp environments, causing greyish-white fuzzy patches that can lead to soft rot of the succulent tissue. It is often triggered by water sitting on the leaves or high nighttime humidity.

Common

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How to confirm: Inspect the base of the white spots for any signs of mushy, darkening, or translucent leaf tissue.

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1 Prune away any affected leaves or stems immediately using sterilized shears to prevent the fungus from spreading to healthy tissue.

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Cutting Tools

$13

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2 Improve air circulation around the plant and ensure you are not watering the leaves directly, as moisture on foliage promotes Botrytis growth.

3 Apply a fungicide to protect the remaining healthy tissue and monitor soil moisture closely to ensure the medium is drying out between waterings.