I have a two year old pond with no visible waterplant growth. I would like to purchase/ or transplant a few Iris, Arrowhead, Sweetflag and Lilies. Can I dig up and transplant these varieties from neighboring ponds without much risk of infestation of other unwanted species? If I purchase some over the internet is there much risk of introducing an unwanted species?
Anything I can do to reduce the risks of infestation during transplanting?

Jeff Gaines