The Jean Lafitte Park consists of three units.  The wild irises are found at the Barataria Preserve in Marrero.   The other units consist of a French Quarter Visitor's Center and the Chalmette Battlefield.

A drive to Jean Lafitte and a walk along the trails and boardwalks in the Barataria Preserve undoubtedly is the longest standing wild iris tradition in the New Orleans area.  Visitors have long trekked down to the Preserve in early spring, and their website even displays a running alert about the bloom status of the irises. 

Check the website, and note several interesting links to more information about the irises.  It is well known, and bemoaned, that the iris population at the Preserve has declined in the years since around 2002, probably due principally to weather events.  They are making a slow comeback, however, and are a case study in the precarious status of our wetlands. Drive down to Jean Lafitte, see, enjoy and learn. 

https://www.nps.gov/jela/barataria-preserve.htm