On 12/29/2014 4:54 PM, Davej wrote:
I did a little preliminary trimming on my grape vines the other day, but then I decided to look on Youtube for some examples -- and I was shocked by the huge size of the cultivated grape vines that were pictured. Now I have huge ~~wild~~ grape vines at the rear of my property, but my domesticated grapes are much smaller (and very old). How much difference should there be in domesticated grapes?

Depends upon the variety, Concord grapes are common and can get quite
large. Other grapes can be much smaller. Other concerns can be the soil
they're in, are they fertilized at all, do they get enough water, etc. I
wouldn't worry to much about them if they're producing regularly.