Impatiens Diseases

Informational table showing disease name, symptoms, pathogen/cause, and management of Impatiens diseases.
Impatiens Diseases - Articles

Updated: August 8, 2017

Impatiens Diseases
DiseaseSymptomsPathogen/CauseManagement
Alternaria Leaf SpotBrown spots and rings form on infected leaves.AlternariaReduce humidity and maintain good air circulation. Space plants for good air circulation. Apply a fungicide registered for use on impatiens.
Botrytis BlightFlowers are spotted and stems rot.Botrytis cinereaReduce humidity and maintain good air circulation. Do not space plants too closely. Remove fading flowers and yellowing leaves. Apply a fungicide registered for use on impatiens.
Bacterial FasciationPlants stunted and have many short shoots at the crown.Corynebacterium fasciansDiscard infected plants. Do not propagate from infected plants. Propagate and plant in pasteurized potting media.
Damping-offStems at the soil line die and plants collapse.Pythium or RhizoctoniaPlant in pasteurized potting media. Keep hose ends off the ground.
Powdery Mildew (New Guinea impatiens)White, mealy fungal growth develops on the top of leaves. Sometimes, heavy gray growth develops.OidiumApply a fungicide registered for use on impatiens.
Pythium Root RotLower leave wilt, leaves fall, and the plant dies.Pythium spp.Pot in pasteurized, pathogen-free media. Keep hose ends off the ground. Apply a fungicide registered for use on impatiens.
Thielaviopsis Root RotRoots become dark brown and rot. Lower stems have sunken lesions when infected.Thielaviopsis basicolaPot in pasteurized, pathogen-free media. Keep hose ends off the ground. Apply a fungicide registered for use on impatiens.
Verticillium WiltLower leaves yellow and fall. Infected plants may recover.Verticillium dahliaePot in pasteurized, pathogen-free media. Do not take cuttings infected plants.
VirusRing spots on leaves. Death of growing tips. Severe stunting.Impatiens necrotic spot virusDiscard infected plants. Control thrips that carry the virus. Do not propagate from infected plants.


Alternaria leaf spot.


Powdery mildew


Impatiens necrotic spot virus symptoms.

Prepared by Gary W. Moorman, Professor of Plant Pathology