Iris Soft Rot
Iris soft rot
Common name
Iris soft rot
Iris rhizome rot
Causal agent
Iris soft rot is a bacterial disease caused by a bacterium from the genus erwinia. It enters the plant through open wounds caused by stress, injury, or borers.
Scientific name
Erwinia carotovora
Symptoms & Signs
The leaves turn yellow and start wilting from the tips to the base. The roots are soft, mushy, and weak, so the leaves easily pull from the ground. It also gives off a strong rotting odor. Unlike most root rot, soft rot is caused by damage to the rhizome instead of overwatering.
Transmission
The optimum temperature for bacterial activity is 82.5° degrees Fahrenheit, while the enzymes need an even lower temperature to activate. It transfers to other plants through infected soil, water, or tools of the workers.
Time of concern
Early summer to late fall
Common hosts
Iris plant