I also like to use water willow (Justicia sp. - not willow trees) and spadderdock. Water willow spreads quickly but it grows in shallow water. I really like to use it for bank stabilization projects. It is very easy to transplant and it takes hold quite well. It's also a great home for inverts and yoy fishes.
In other parts of the country, I've heard of spadderdock becomming overpopulated quickly. This almost certainly true, but once again, I haven't had any problems with it in my area. To qualify this statement, I should note that I plant the spadderdock in plastic containers. I also do the same when I plant fragant water lilies.
