Well, I am growing both Petasites japonicus 'Variegatus' and P. japonicus. They are behaving but I am aware that they could spread rapidly. I, too, like the large leaf tropical appearance; however, mine are still quite small.
You may want to try them in the woods.........

{{gwi:363961}}

terramadre, thanks for the pics. You've convinced me that 'Variegatus' is the one I've got to have. A couple more questions: Do you have yours planted in a wet area? If not, do you have to water it to prevent wilting when we have a hot, dry period? My property is all pretty high on a mountain ridge and I have plenty of shady areas, but its all very well drained. And if you don't mind me asking, did you acquire yours locally or buy online? I've found it available from Brian's Botanicals so I may order it from him if I find its not available in the B'ham area.

thanks again,
john

Whiteflower Farm's on-line catalogue says it's called "pestasites" because of its tendency to become invasive. You might want to read their review at http://www.whiteflowerfarm.com/35780-product.html. Forestfarm.com says it's "edible (& potentially invasive)" Their pictures are intriguing, though. Do you suppose you could keep it contained and moist by planting it in a large pot sunk in the ground and filled with good soil and perlite or vermiculite or some such?

John,
The plants were passalongs from our local plantaholic ;-)
They are growing in heavy clay and in the shade. There are no wet or even constantly moist areas on the property. I only water when we have drought conditions.