To obtain the full wetland benefits this plant offers, allow old vegetation to persist through winter. This will create a barrier that will discourage any unwanted visitors such as nesting geese in very early Spring. If desired, after fall frost has set in, any desiccated leaves can be cut back to about 1″ above the crown.
Root stocks (corms) may be fed upon by aquatic rodents, such as beaver, muskrat, and groundhogs. Snails may eat the foliage. Various rots can occur, such as rhizome rot, crown rot, and bacterial soft rot. Susceptible to Iris borer, Iris thrips, and aphids. Aphids can transmit the mosaic virus. Be sure to sterilize your pruners after every cut.
Deer problems in your area? Iris is one plant that they leave alone, likely due to its unpalatability.