Before I get a call from someone telling me that there has been a terrible act of vandalism and some of the yellow irises have been removed from the pond near the cabin, let me explain.
The yellow flags are Iris pseudacorus, an exotic species from Eurasia and northern Africa. In addition to being non-natives, they are terribly aggressive. Those of you who have been visiting the preserve for several years may have noticed that the original clump has grown huge, and they have spread to the other side of the little pond and started down the drainage toward the lake.
Yesterday, April 20, I spent a half day digging irises (and this morning I am so sore that I can hardly walk). I concentrated on removing the youngest part of the colony--in other words my goal was STOP THE SPREAD! There will have to be a followup operation. It is next to impossible to remove every part of every rhizome, and wherever there is a piece left, I suspect there will soon be a new plant. But at least the first step is taken. Thanks to Jim Willis for hauling off the plants which I dug. He will dry them out and burn them!
Geraldine had, on one occasion, hired a young man to remove them. Unfortunately, he did not remove the rhizomes, so it was an exercise in futility. I suspect that it is going to take a couple of years, at least, to finally get them out. And I hope that I am not being overly optimistic.
It is becoming apparent that all land managers are going to have to devote more and more resources to the control of exotic, invasive plants. At Watson Preserve, our exotic pests at this time include torpedo grass, Japanese climbing fern, Chinese tallow trees, the yellow flag iris, alligator-weed and Mexican ruella. I'm sure there are others.