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Carnation (Dianthus) Diseases

Name: Carnation (Dianthus) Diseases
SKU: ART-3701

Informational table showing disease name, symptoms, pathogen/cause, and management of Carnation (Dianthus) diseases.

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Updated:

June 30, 2025

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Disease	Symptoms	Pathogen/Cause	Management
Alternaria Leaf Spot	Small purplish spots form on leaves. Their centers become brown while the leaves yellow.	Alternaria dianthicola or Alternaria dianthi	Apply a fungicide to protect healthy plants.
Bacterial Slow Wilt or Stunt	Wilting, twisting, curling, and stunting of lower leaves and side shoots followed by the death of lower leaves. Wilted plants may recover only to wilt again. Stunted plants have narrow, yellow-green leaves. Symptoms require several weeks to develop.	Erwinia chrysanthemi	Grow in raised beds pasteurized between crops. Use culture-indexed cuttings free of the pathogen. Destroy infected plants.
Bacterial Wilt	Leaves turn gray-green, then yellow, and then die. The roots rot. Vascular tissue browns. Cracks develop in internode tissue. Slime oozes from these cracks when humidity is high.	Pseudomonas caryophylli	Pot and propagate in pasteurized raised beds. Use clean, disinfested tools. Use culture-indexed cuttings free of the pathogen. Destroy infected plants.
Botrytis Blight	Petals turn brown and are covered with gray, fungal growth.	Botrytis cinerea	Space plants to ensure good air circulation. Maintain low humidity. Avoid watering late in the day. Remove crop debris. Apply a fungicide to protect healthy plants.
Fusarium Wilt	Lower leaves yellow and wilt up one side of the plant. Symptoms progress up the plant. The top of the main shoot grows at a right angle to the main stem. Late in the disease, the roots and stems rot.	Fusarium oxysporum	Pot and propagate in pasteurized raised benches. Use culture-indexed plants free of the pathogen.
Fusarium Stem Rot	Reddish-brown spots at the base. No vascular discoloration occurs beyond the rotted area.	Fusarium graminearum, F. avenaceum, or F. culmorum	Plant only healthy, pathogen-free cuttings in pasteurized, raised beds.
Greasy Blotch	Small, web-like patterns give leaves a greasy appearance. The leaves turn yellow and die.	Zygophiala jamaicensis	Maintain relative humidity below 85%.
Phialophora Wilt	Plants wilt, leaves yellow, and vascular tissue is discolored dark brown.	Phialophora cinerescens	See Fusarium wilt above.
Rhizoctonia Stem Rot	Stems at the soil level have a lesion with a brown border. Stems have a dry, shredded appearance.	Rhizoctonia solani	Plant in pasteurized, raised beds. Apply a soil drench to protect healthy plants.
Rust	Small blisters containing rust-red spores form on leaves.	Uromyces dianthi	Apply a fungicide to protect healthy plants.
Viruses	Leaves may be mottled, have yellow spotting, dead flecks, line or ring spot patterns. The plant may be distorted or have flower color breaking.	15 different viruses are known.	Plant virus-indexed cuttings. Maintain good insect and mite control. Destroy infected plants.