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Fern Diseases

Name: Fern Diseases
SKU: ART-4158

Informational table showing disease name, symptoms, pathogen/cause, and management of Fern diseases.

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Updated:

July 7, 2025

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Leptosporangiate fern

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Disease	Symptoms	Pathogen/Cause	Management
Bacterial Blight (Asplenium, Bird's Nest Fern)	Translucent spots develop all over the leaves, enlarge quickly, and turn reddish-brown with purple halos.	Pseudomonas cichorii or P. gladioli	Purchase plants free of the disease. Avoid overhead watering. Discard infected plants.
Graying (Nephrolepsis, Boston fern)	Leaves have a gray color, and plants have few runners.	Drought	Maintain even soil moisture at all times. Examine roots for nematode and root rot symptoms.
Foliar Nematode (Asplenium)	Small dark green spots form at the base of fronds. Spots turn brown to black as they enlarge.	Aphelenchoides fragariae	Discard infected plants. Avoid wetting the fronds when watering.
Frond Lobing (Asplenium)	Fronds have many lobes and indentations. Frond tips may be crinkled or dead.	Over-fertilization	Reduce the amount of fertilizer being used and leach the pots.
Leaf Tip Burn	The tips of fronds and leaflets brown and die.	Over-fertilization	Reduce the amount of fertilizer being used and leach the pots.
Nematodes	Foliage grays, wilts, and dies. Roots are rotted.	Pratylenchus sp.	Pot in pasteurized potting mix. Discard infected plants.
Pythium Root Rot	Plants have a gray color or are yellowed, stunted, and wilted. Roots are brown and rotted.	Pythium	Plant in pathogen-free, pasteurized potting mix. Apply a fungicide to protect plants.
Rhizoctonia Blight	Brown, irregularly shaped spots form on the foliage close to the crown or sometimes at the top. Spots spread very rapidly. Webbing of the fungus forms from frond to frond.	Rhizoctonia solani	Plant in pathogen-free, pasteurized potting mix. Apply a fungicide to protect plants.