P&PDL Picture of the Week for
March 16, 2009

Daylily Leaf Streak---An Ounce of Prevention is Worth a Pound of Cure

Gail Ruhl, Senior Plant Disease Diagnostician, Department of Botany & Plant Pathology, Purdue University

Daylilies are one of the most popular perennials grown in the United States. They are pretty, easy to grow and relatively low-maintenance. There are, however, several different fungal diseases that attack the foliage of daylily. If your leaves exhibited spotting and dieback last year and you did not remove the infected, dead, foliage last fall, the fungal spores likely survived the winter in the dead leaves and stems at the base of the plant and are just waiting to infect the new growth that emerges this spring.  It is not too late to reduce the chance of infection from pesky fungal diseases such as daylily leaf streak. You can still remove last year’s dead leaves from around the base of your daylilies.  Your reward for good garden sanitation will be healthier, ‘happier’ daylilies.

Photos 1 & 2 courtesy of Karen Rane, University of Maryland

Photo 3 courtesy of Gail Ruhl, Purdue University

Photos 4 & 5 courtesy of Tom Creswell, Purdue University


Click on image to enlarge

Improper Garden Sanitation -

Daylilies emerge in the spring through infected plant material that was not removed last fall

Spring Clean-Up-It’s Still Not Too Late! -

Dead plant material can still be removed from around newly emerging plants to reduce the chance of infection.  Thorough removal and destruction of last year’s leaves and plant debris from the planting site is recommended for best results.

Daylily leaf streak

Daylily leaf strek

Daylily leaf streak

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service