[MickyB]

I have two grape vines coming 'Vitis Reliance and Himrod' and I am in the process of erecting a sort of pergola type frame for them to grow up (photographed below), the wooden bars that you see spanning the width are not secured in place, I just put them there to see what they looked like, how far would you space these bars apart? I had an idea that the vine would creep up the trellis and across the bars with the grapes dangling down in bunches on the inside (although I guess they probably wouldn't get enough sun to ripen them if they did?) Any other general advise appreciated.

[Trillium]

I did a similar main structure but without the trellising. Instead, I ran lines of coated clothesline wire through eyescrews for about 4-5 levels and that seems to be working fine. I'd keep the top 'hatching' since they'll eventually crawl over it and onto you without it. A shame the boards at the fence have to be there as they'll block sun somewhat.

2 plants would be enough for that length. They start out small but when they get firmly rooted, look out!

[MickyB]

Thanks 

The 'pergola' is about 16ft long and the gap is about 4ft, I have heard that vines are vigorous growers hopefully I will be able to keep them under control.

The boarded side is the boundary to the neighbouring plot and I have some screening to tidy it up but it will have to stay 'closed' on that side although the other side will get full sun.

[Trillium]

If the planted side gets the sun, then you'll be fine. And yes, some varieties turn into triffids. The varieties I bought were supposed to be small, restrained dessert grapes but quickly turned into rampant monsters that would grow 30 feet each side, each! I have to do a lot of pruning through the season or it would become a tangled mess. Hope yours doesn't turn into a triffid 

[MickyB]

Will the vine be able to grow up the trellis or will I need to add wire supports for it to attach to?

[Trillium]

They'll usually do some climbing on their own, but usually right over one another in a tangled mess, so I used some baling polytwine that I had and tied them at better spacings along the wires or to the vertical support posts, then across the tops so they wouldn't flop down on people and scare them     in your case, just some pieces of string/twine/whatever tied to the trellis at good spacings will work just fine. I didn't have any trellising on my grape arbor which is why I used the wires which let in maximum light.

[MickyB]

All finished and grape vines planted, I am very pleased with how it looks. 

[Trillium]

Very  nice