I planted 36 Navahos last fall. They potted, 2 year old plants each with a single, spindly cane.
I had prepared 3 60' berms/rows for them. They were planted 4' apart with extra space in the middle and ends of the rows. My original plan was to prune out the floricanes this year after new primocanes started.
These things are growing crazy! The primocanes ended up growing with such vigor before I pruned anything that I decided to leave most of the floricanes to see what would happen. Looks great so far - quite a few berries and a ton of new canes that are already ready to be tipped.
These are an upright, thornless variety so I installed a simple trellis system. 3 t-posts and two electric fence wires for each row. One wire at 2' and the top wire at 44". The new canes are sturdy enough without support, but we get some wicked winds here. The trellis is to provide support for heavy wind and to tie in laterals, which I'm planning to let grow without pruning for part of them. I've read two different approaches to laterals; let grow and tie in, or prune to 18". I'll see next year which works best for this variety in this area.
Overall I'm happy with this variety, but wild is the only thing I have to compare them to.
Speaking of wild, in this area wild blackberries are considered weeds - they are everywhere. I planted blackberries because I've too many seasons where the rain spigot gets turned off about two weeks before the berries are ripe. I figure cultivated berries will be more reliable and require less donation of blood to thorns, ticks and chiggers.
The estimated crops for these are 10 - 30# per plant. I planted 36 so I can mange for max, but still have better than 150# if I only get half of the lower estimate. IOW, I want to ensure more berries than I can use
I'm taking the same approach with elderberries.
I'll add pics when I get a chance ...