Eric notices the Iris are planted in what look like little troughs. He assumes that must be important for their growth and survivability. It is. Louisiana Iris really like to have their feet wet so the way these troughs are designed is the cement trough is higher on the backside than on the front. They keep the water in. They actually lay a little soaker hose in the trough which keeps the plants watered. And, this method should work at home as well, if trying to grow this species. Also, they do have to periodically divide the Iris, the trough makes it easier to divide them. One can put a flat shovel down one side and lift up because it has a bottom.