Gathering nodes are multiples of 5. What level do you have to be to gather from a node?

I realize that when a node first becomes accessible the harvest success rate is low, but I like to think ahead about what to gather when I go off on a quest or whatever... and if there's a certain item I just need a few of, it's worth failing a bit. But there's nothing worse than going out of your way for nodes you can't see/access ><