Elston Gunn wrote:

Is the old adage one gallon of wine per vine
true? I have a small lot and would like to
plant enough to make a carboy (6 gallon/23L) per
year. About how many vines would I need? And,
am I looking at about 4 years from putting the
vines in the ground to picking my first grape?

You are looking at about 3 years to get your first
small harvest. Your yield will depend on variety
and how you crop them. I have learned that it
does no good to have large crop load to produce
extremely week bodied wine. For some varieties a
more realistic yield would be somewhere around 8
to 10 lbs per vine without overcropping. This
would mean that that to make 6 gallons of wine
you need about 75 lbs of grapes so you can back
calculate how many vines you need.