haha no i don't know who put them there...
Though, I was thinking the other day "Wouldn't it be funny if someone grew weed in a very populated public area and it went undetected for some time"... well there you go!
The majority of the population in my town is a much older crowd (senior citizens and such) and it seems most of them wouldn't even know what a weed plant looked like. I don't know who discovered it, but it's downright hilarious that it happened.
Auntmary: unfortunately they have been removed, as the article stated in the end :/