grapes pic

first year with grapes on but all is not well or is this normal grapes look like they have exploded??

And you were not wrong

They look fab, what variety are they?

They do look rather good 

How many years from planting does it take to get a crop from them? And how much space do they need?

You can get a crop the first or secons year, but if you deny yourself a little longer the plants will be stronger for it in the long run.

I'm planting three vines per 12' x 2' bed, i.e. 4' apart, but this will require annual training and pruning.

Growing them free-standing that's about the minimum seperation (with 6' between rows, I'll have a 3' bed in the middle for other crops).  The alternative is a pergola or trained up a sunny wall.

I'd love to try one in my polytunnel, but I suspect it would take a lot of light away from everything else in there. By the look of yours it's a better bet for a crop than the melon I planted in there this year, which has just finally started showing baby fruit