You must go to Danger Woods to purify the tainted water before anything can repopulate.

i got my fairy moss from the swamp...keep trying!

YOU SEEM TO BE IN A PIKAL RIGHT?
WELL YOU SHOULD TRY TO COMPLET EVERTHING ELS THEN KEEP GOING TO THE NEXT @$%#^@$^%***
DAM AND THEN GO BACK TO THE SWOMP THEN YOU WILL HAVE YOUR ANSWER!
NO PROBLIM

go to the place where the toxic waste stuff is leeking and then make a dam so theres no
poluted water then put the hyisinfes in then the fairy moss will grow round it (well at
least my cosin told me this so if it dont work blame my cosin):)

check your backpack for any fairy moss seeds real good. if you can find them, just wait by
some fully grown fairy moss it just might take a little while. and if tHAT doesnt work,
stop the polution in danger woods. and if THAAAT doesnt work.. youre skrewd.

i got it on caslte hill, have beaver dam it, the grow a lot of water hyacinth, fairy moss
is attacted to it. then all u have to do is wait, i did and before i knew it fairy moss
was growing with it ,it grows quickly and speads nicely