Hosta Diseases

Informational table showing disease name, symptoms, pathogen/cause, and management of Hosta diseases.
Hosta Diseases - Articles
Hosta Diseases
DiseaseSymptomsPathogen/CauseManagement
AnthracnoseLarge, irregular to round tan spots with dark borders sometimes have the centers of the spots fall out. Small black dots (fungal fruiting structures) may be seen in the spots.ColletotrichumRemove infected leaves. Irrigate plants in a manner that keeps water off the leaves. Apply a fungicide to protect healthy leaves.
Petiole rotLeaf stems brown at the soil level as leaves turn yellow, then brown, wilt and die. White fan-like fungal growth at the base of the plant eventually has small, black structures on its surface.Sclerotium rolfsiiDo not pile mulch or soil around the base of plants. Remove infected plants. Take care to not spread the black fungal structures elsewhere in the garden during plant removal.
Fusarium root and crown rotInfected plants are stunted and emerge unusually late in the spring. Leaves yellow, brown, and die. Stems at the soil line have a dry decay that is brown to black in color.Fusarium hostaeRemove infected plants. During transplanting, take care to not wound roots or stems.
Bacterial soft rotPetioles and lower leaves have a wet decay that smells badly as leaves yellow and wilt.PectobacteriumRemove infected plants. When dividing plants, thoroughly clean and disinfect knives and other tools that come in contact with the plants. Wash hands thoroughly when finished with one plant before going to the next.
Hosta virus XMosaic, yellowing, and death of leaves can occur. On variegated varieties, colors may bleed into one another severely affected leaves may wither and die.Hosta virus X (HVX)This virus is very easily spread from plant to plants on hands and tools. Destroy infected plants and wash hands and tools thoroughly after working on one plant and before moving to the next. Do not divide infected plants.
VirusesVirus infections cause a variety of symptoms including discrete circular, concentric rings that look like a target spot and yellowing and puckering of leaves.Impatiens necrotic spot (INSV), Arabis mosaic (ArMV), tomato ringspot (ToRSV), Tomato spotted wilt (TSWV) virusesPurchase only healthy, symptom-free plants. Destroy infected plants. Do not take cuttings from or divide infected plants since new plants will carry viruses. Control thrips that spread INSV and TWSV.
Foliar nematodesStripes of light green to yellow areas parallel to the major leaf veins form on older leaves. Affected areas turn brown and result in leaves having a dry, tattered appearance.Aphelenchoides spp.Purchase plants with no symptoms. Water in a manner that does not wet the leaves. Splashing water spreads foliar nematodes. Remove and destroy leaves with dead areas.
Root knot nematodeSmall galls or swollen areas form on roots and may cause root tips to branch close to the tip. Plants may be stunted, wilt easily, and appear to be nutrient deficient.Meloidogyne spp.Destroy infected plants and avoid replanting hosta in an infested area.

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Authors

Gary W. Moorman, Ph.D.