Chrysanthemum Derlei Dark White Powder - Causes & Fixes

Jump to cause: Powdery Mildew Mealybugs Whiteflies

search Possible Causes

error

Powdery Mildew

This is a fungal disease caused by Oidium species, which thrives in high humidity and poor air circulation around the dense foliage of Chrysanthemums. It manifests as a characteristic white, flour-like coating on the leaf surfaces.

Very Common

lightbulb

How to confirm: Inspect if the white patches appear dusty and can be rubbed off with your finger.

build How to fix it

shopping_cart Recommended Products

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

Bonide Captain Jack's Copper Fungicide 32 oz

0.9 L • 1 pcs • Organic

$12

In Stock

2 Prune and remove heavily infected leaves to reduce the fungal load and improve airflow around the plant.

Fiskars 5/8" Bypass Pruning Shears

Cutting Tools

$13

In Stock

3 Increase air circulation around the plant and avoid overhead watering to keep the leaf surfaces dry.

warning

Mealybugs

These small, soft-bodied insects secrete a white, waxy substance that looks like powdery residue or cottony tufts on stems and leaf axils. They feed on the sap of the Chrysanthemum, weakening the plant's vigor.

Common

lightbulb

How to confirm: Use a magnifying glass to look for tiny, moving insects nestled in the crevices of the stems.

build How to fix it

shopping_cart Recommended Products

1 Treat the plant with an organic insecticide to eliminate the mealybug infestation and kill existing insects and larvae.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Carefully wipe away the visible white waxy residue from the stems and leaf axils using a cotton swab dipped in isopropyl alcohol.

3 Isolate the Chrysanthemum from other houseplants to prevent the mealybugs from spreading to healthy plants.

warning

Whiteflies

Infestations of whiteflies can result in a fine white dust-like appearance on the undersides of leaves due to their presence and excreted honeydew. They often emerge in a 'cloud' when the plant is disturbed.

Common

lightbulb

How to confirm: Gently shake the plant and observe if a small cloud of tiny white insects takes flight.

build How to fix it

shopping_cart Recommended Products

1 Apply an organic insecticide spray to the undersides of the leaves to eliminate adult whiteflies and larvae.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Place yellow sticky traps near the plant to capture emerging adults and monitor the infestation level.