Hemerocallis (Daylily) Diseases

Informational table showing disease name, symptoms, pathogen/cause, and management of Hemerocallis (Daylily) diseases.
Hemerocallis (Daylily) Diseases - Articles

Updated: August 8, 2017

Hemerocallis (Daylily) Diseases
DiseaseSymptomsPathogen/CauseManagement
Colletotrichum leaf spot or leaf scorchLeaf tissue dies in a streak along the mid-vein.Colletotrichum dematiumRemove infected leaves. Destroy leaf debris at the end of the season. Avoid overhead irrigation.
Leaf streak or Red leaf streakReddish fleck form on the leaves as the mid-vein yellows. Oval dead spots form and the leaves die prematurely. During wet conditions wet, shiny masses of white spores can be seen with a hand lens on the brown leaves.Aureobasidium microstictumRemove infected leaves. Destroy leaf debris at the end of the season. Avoid overhead irrigation. Cultivars vary greatly in susceptibility. Apply a fungicide to protect plants.
Rhizoctonia crown rotSlender, grassy foliage develops and few flower stalks form. Crowns rot and die.Rhizoctonia, usually following freeze injury.Protect crowns from freezing.
Russet spotReddish spots form on the leaves.Unknown.
RustBright yellow spots or streaks on the upper side of the leaf have bright yellow-orange spores on the underside..Puccinia hemerocallidisThis fungus also occurs on Patrinia spp. (and possibly Hosta, but this has not been observed in the U. S.). Most cultivars are susceptible. Remove infected leaves and immediately place them in a plastic bag for disposal. Keep the bag closed. Apply a fungicide to protect plants.

References

  • Holcomb, G. E. 1976. Daylily leaf-streak in Louisiana. Plant Disease Reporter 60:232-233.
  • Blosser, W. 2001. Daylily rust alert. Regulatory Horticulture 27:5-6.

Prepared by Gary W. Moorman, Professor of Plant Pathology