I have a small spot in my yard that is constantly wet or flooded due to the way water drains off a nearby hill. It is only about 8ft around. I was thinking about filling it in with dirt but I was wondering if I could grow something different instead. Any idea how to get cattails growing here? Dig 'em up at a nearby drainage ditch? Seeds? I was also considering bamboo or a birch tree but this would be more entertaining.