..water the..dead flowers..adept builders..won't stay to water them..
I used master builders who were also master farmers and even then they would get their own ideas and wonder off. You just have to be on top of them constantly.
What to do if one of your good villagers is weakened
In VV2 there is something you can do to help weakened villagers. In VV1 you could assign them duties that are less likely to get them injured and perhaps feed them but there is nothing similar to what you can do in VV2.