I just "made friends" with some little mages and told them to water my place... and the website said
"Each creature will only work for around an hour and 40 minutes (about 80 squares) until it needs rest and automatically returns to the barn"
but mine arn't doing even 1/4 of that...
how do you get them to water faster?
Brush them every day and get their friendship level up.
You could also get more watering monsters and have them all water... one will pick up where the last one left off till they are all done. no guarantee that all you plants will get watered though.