Re rootstock - 1103P‘s vigor was one of my concerns with using it - that and it’s not a perfect match for low ph soil. I’m amending with lime but you never know exactly where the ph will end up. The 3309 does better with the low ph soil and has less vigor - so was my first choice. More water isn’t much of an issue - I’ve got a very strong well and solar panels so I can pretty much water as needed.
I’m planning to plant with 12 foot aisles and 6 feet between vines. I will have to play with vine spacing a bit as each row is a different length. The West side end posts will be square to the fence but the east side end posts will be at a diagonal parallel to the East fence as my lot is really far from square. So the uphill rows (south side) will be about 170 feet long and the northern most rows about 120 feet. The Zin/primitivo vines will be on the South side - so in the longer rows. when the time comes, I’ll play with the plastic forks and see if I can tighten things up a bit.
Re the Zin/primitivo discussion, I’ll chat with some neighbors and commercial wineries and get more data. I have to live with these choices for a long time so would rather get it right the first time. Thanks for the input.
Regarding uneven ripening of Zin, I’ve noticed that my neighbor with the 100 plus acres of Zin picks their vineyard multiple times. The same vine may get picked as many as three times. Perhaps that is one way, in a large scale vineyard, to deal with the problem. I have definitely seen my home batches of Zin have 3 and even once a 4 point climb in brix after the crush. it did eventually finish primary but it was a challenge. But that’s a topic for another thread.