There's at present no approach to buy weed. There won't be any cannabis retailers. You need to grow it your self or be a part of a cannabis club. Yet another way of getting weed in Berlin is with the street dealers present in Görlitzer Park and Volkspark Hasenheide. https://charliefgbyq.eedblog.com/35347008/the-best-side-of-where-to-buy-weed-in-berlin