Some years ago I planted a nursery pot of these because I liked the yellow color. It got maybe 3-4 blooms each year, but the foliage slowly spread a bit. I blamed the lack of blooms on the soil which is very sandy and usually dry there.

A few years ago I learned that the plant is considered invasive in wetlands. I wasn't concerned due to my dry soil. Last year I gave a shovel full of Virginia Bluebells to my next door neighbor, Elaine, along with a bit of the above Iris. I did warn her about the invasive bit. Both bloomed this spring! A successful transplant!

Last evening, I was prying up some rocks that had sunk below the dirt along a curved pathway. To my dismay, I saw a mass of reddish rhizomes along the back of the sunken rocks. It was the iris!

Today I spent four hours digging out the mass of rhizomes, helped by a jet of water from the hose to wash away the soil. They even had tunneled below a shiny mass of European Ginger and a light blue transcantia. I couldn't dissect them in place, I ended up taking the entire 12" x 18" mass of them out. At the other end of the iris, the rhizomes had tunneled under another 15" of a blooming dwarf hosta. That, too, had to be taken out entirely!

I will try to save some of the European Ginger, it is my only patch and has beautiful dark green glossy leaves. The batch under the hosta will be tossed, I have plenty of that.

Lesson learned - this Iris Pseudocorus is invasive in ALL soils, regardless of moisture or lack thereof. I will have to tell my neighbor tomorrow and dig out her small bit!