Daylily Perennial Shrub Diseases:

 

Colletotrichum Leaf Spot or Leaf Scorch:

Symptoms-Leaf tissue dies in a streak along the mid-vein.

Management-Remove infected leaves. Destroy leaf debris at the end of the season. Avoid overhead irrigation.


 

Leaf Streak or Red Leaf Streak:

Symptoms-Reddish 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.

Management-Remove infected leaves. Destroy leaf debris at the end of the season. Avoid overhead irrigation. Cultivars vary greatly in susceptibility. Protect new leaves with thiophanate methyl.


Rhizoctonia Crown Rot:

Symptoms-Slender, grassy foliage develops and few flower stalks form. Crowns rot and die.

Management-Protect crowns from freezing.


Rust:

Symptoms-Bright yellow spots or streaks on the upper side of the leaf have bright yellow-orange spores on the underside.

Management-Remove infected leaves and immediately place them in a plastic bag for disposal. Keep the bag closed. Apply flutolanil, azoxystrobin, mancozeb, or chlorothalonil, weekly.