and since
they grow in relatively shallow areas do not have to worry about them
taking over my entire pond.

Don't be to sure of that.... I just pulled some out of a friends 3 foot deep
pond and there wasn't much pond area left for the fish when I got there.....
They were no shorter then 7 foot tall and growing like mad.... they also
punctured the liner.
Colleen
zone 5 Connecticut.