For banjo-afficionados there is a place in Northern Germany: The next Banjoree will happen September 13th - 15th in Proitzer Mühle, which is  1 1/2 hour south/east of Hamburg - if you take a car. Paddling with your banjo on the river Elbe could cost you some more time.
Unfortunately I will not join the Banjoree this time (never thought I would miss a banjoree, but this year´s timing is quite difficult for me). But all others pickers, frailers or strummers should go there for sure.