causing organisms (pathogens) and environmental conditions
all play a role in crown and root rots of plants. Daylilies
are susceptible to fungal rots caused by organisms
such as Fusarium, Phytophthora, Sclerotium, Rhizoctonia and Pythium,
as well as bacterial soft rot involving Erwinia.
Very recently (2004) daylilies have been discovered
susceptible to Armillaria, or shoestring root
rot. Symptoms of rotting can include poor growth, wilting,
yellowing of leaves, obviously mushy tissue and death
of the plant. Bacterial soft rot is well known for
its particularly foul smell.
overfertililization and other poor soil conditions
and plant stresses favour rot diseases. While fungal
pathogens can invade intact plant tissue, bacteria
can only infect through existing openings such as
an injury from garden tools, pests, other diseases,
frost damage etc.
where daylily rot is frequent, assistance in diagnosing
the cause can be obtained by submitting a diseased
plant to a diagnostic laboratory. Contact your local
Master Gardeners or Extension Office for information
on where to send a specimen.