I can't seem to find a good online source about growing concord grapes.

I live in southern NH near the coast.

What I'd like to know is:
1) How much do I prune and when?
2) How should I amend the soil to maximize fruit production? (In my second
year, I only got two small bunches of grapes)
3) How big of a trellis should I build? (right now I have it growing on two
6 ft fence posts with wire fence between them)

Any help here or pointing me in the right direction would be greatly
appreciated!

Thanks in advance.
-Kevin
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