I was very happy to see this iris blooming last weekend and for a couple of reasons. First, it is a survivor. It is growing in the shallow edge of the New Orleans City Park lagoon that is a remnant of old Bayou Metairie. The City Park lagoon system is connected to Lake Pontchartrain via Bayou St. John, another remnant waterway that at one time was part of a system of canals that connected the Lake with the commercial district downtown. That was back before there were roads all the way out to the lakefront.
Storms can push brackish Lake water up Bayou St. John and into the lagoons. After the levees failed in Hurricane Katrina, it wasn’t primarily the open Bayou that channeled the salty water; the water poured through the breeches to the tune of seven feet and more in some areas the City. Plant life suffered unbelievably and the irises were among them.
Some varieties of Louisiana iris are a little tolerant of salt water, but prolonged exposure will kill them. Because a drought after Katrina denied a good flushing with fresh water, there was quite a bit of damage, and salinity in the lagoons remained high. I grew Louisianas not far from the Park in half barrels with no drain holes, and the salt water could not get out during the six or so weeks that passed before I could return. A few were entirely dead and all were badly damaged. Removed from the barrels though, they did recover well.
To all outward appearances, the City Park lagoons look like a natural home for Louisiana irises. And before New Orleans became entirely developed, there were vast numbers of native irises growing in what were cypress swamps and low areas. After Katrina, the salty lagoons did not seem so hospitable.
Today there is better control of the entry of brackish water as a result of a weir and fresh water pumps that add good salt-free water to the mix. A few years ago as the lagoons were in recovery, a group of local iris enthusiasts planted a large number of rhizomes along the banks of Bayou Metairie, including some down in the water. It does appear that a number did not make it, but last weekend there were many scapes up with buds about to open. And the early bloom in the picture showed that the lagoons are indeed a habitat in which Louisiana irises can grow. Another big storm will provide a better test, but so far, so good.
The second reason this picture made me happy is that a Louisiana iris just looks so “right” blooming in water. The flowers and foliage have a graceful form. Both wild and hybrid Louisiana iris flowers can be showy, but the plants are not just a vehicle for gaudy blossoms. There are different flower shapes but this flaring one is my favorite. It approximates the natural shape of the species I. giganticaerulea.
Louisiana irises irises look good on dry land, too. Most people grow them in ordinary flower beds, and as long as they don’t dry out, they do just fine.
City Park is 1300 acres large. It has made tremendous strides in recovery from Katrina. In fact, it is booming. Those interested can take a look at its website, including a map that shows the lagoon system. http://neworleanscitypark.com/mapofpark.html The Bayou Metairie remnant is in the lower right. Bayou St. John runs the entire length of the park along the right side of the map.