The idea behind getting them to sprout is to just keep them from drying out at this point. Think about it, that little rhizome is just trying to send out some roots to become established while at the same time, using energy to send up a few shoots. It's water needs aren't too demanding, just enough to make sure the soil doesn't dry out. Once the plant begins to show some serious growth and has developed a bunch of foliage, now it has a way to 'lose' water through it's leaves: http://biology-forums.com/index.php?topic=5789.0
. Yes, homework is part of growing hops. So, in the beginning, the water needs are minimal but as the plant grows into a monster with tons of foliage, the water needs increase. Rule of thumb, better to be a little light rather than heavy with the water, you can always add more. And as always, when working with plants, patience is a virtue. Hope this helps.