I am growing some jumbo blackberries this year and I needed to see how to do it. Grow organic peaceful valley has a great video on how to grow brambles.
I learned a lot from her.
https://www.groworganic.com/organic-gardening/articles/cane-berries
‘Arapaho’ Thornless Blackberry Plant – 2×3″ Pot – The Earliest Blackberry
‘Apache’ Thornless Blackberry Plant – 4″ Pot
2 yr old stock – Heritage Raspberry
2 yr. old stock – Golden Raspberry