Growing raspberry plants from seed.
I would like to know what can be done to assure germination and success. Before anyone asks why don't I just buy plants, there is a bit of a story involved. My parents' 3 acre property in Wisconsin was sold 4 years ago, after my father passed away at 97. It had been my grandparents before, and they had planted an extensive orchard, and many different kinds of raspberry plants. My brother and I grew up taking care of those plants and enjoying the fruit. As time passed I'm guessing the varieties must have interbred: so what kind they are, I could not guess. At least one kind was originally Latham.
My brother's son also lived there for a while as a young adult to take care of his grandpa. While staying there he began to get very interesting in gardening, especially growing fruits and vegetables.
My brother and nephew went there last summer, to see how the place looked. The raspberries were past eating, the current owners don't pick them, I guess. But some seeds had matured. My nephew picked a few branches, saying he wanted to try growing them. My brother saved them and planned to ask me how to do it.
My nephew passed away unexpectedly in early September, aged only 24. Now my brother would really like to grow those raspberries more than ever, as a connection to both my parents and his son.
Can anyone tell me how to make this happen? Thanks for any advice!