Transplanting Grape Vines

[DavidW]

I purchased tree vines last autumn, all of which have been kept in my greenhouse over the winter. The plants are presently approx 8" high, my questions are: -

1.   When can I transplant them onto my allotment?
2.   When I plant them, do I need to prune
3.   If so how much.

Thanks
David

[DavidW]