Can anyone help me with this puzzle (on the Windows/Mac version)?

I've completed Puzzle 4 (unblocking the creek), and have sent a villager to examine the dead flower field. They go to fetch some water from the creek and water the field, then nothing happens. Is there something else I'm supposed to do? Or am I just being impatient??

Any hints much appreciated =)

You have to be patient. While any villager will make the trip to water the field, only builders will keep at it without supervision.

It takes a while. They finished mine while I was away. You'll need to be patient, or let more of them bring water.

Some might do it on their own though.