Water Gardening: Petasites, anyone?, 1 by

wrote:
Hi, My experience with Petasites is that it's very invasive if given a free roam to grow. This is what I have done to eliminate that growing habit.

I have used a 5 gal. containter then lined it with a screen the type used in a screen door the roots are then contained in the container. I then bury the container into the ground. This should work well around a pond area and they do require a lot of water during the summer. You may require a rock or two on top of the container rim to keep it into place, it can become top heavy with it's large leaves. It will become root bound in it's first year so you will need to divide or place into larger container.

I also have used the 19 gal. tubs with rope handles and completly bury the container into the ground. You will need to drill some holes on the bottom of the container for drainage. One plant became root bound in its second year in this large container so that can give you some idea how invasive the roots could become if not contained. The large leaves do give a great focal point to a garden area that is partially shaded.
Some of mine are blooming right now and here is a picture.