Grapevine in a tub/pot

[Lymmguineas]

I'm thinking of growing grapes for the first time.
I've got a 12' by 8' greenhouse with a paved floor.
It's not practical to lift a slab to plant directly in the ground so I was thinking of growing in a large pot or tub.
Would this work?
If so, what variety would people recommend?
When is the best time to plant?
Do I need more than one vine?
Any advice gratefully received!
Thanks.

[ameno]

Vines can be grown in large pots of soil (not compost), albeit with reduced yield. However I don't think this would be practical in a greenhouse. You have limited height in a greenhouse as it is, and with a pot 2 feet or so deep you lose even more height.

It's also worth pointing out at this point that greenhouse vines are often grown with their roots planted outside of the greenhouse, and the vine then trained in through a gap in the glass. Maybe this would be an option for you, and would allow you to plant in the ground on the outside of the greenhouse?

Vines are all self-fertile, so one should be enough for pollination.
Early winter is the best time to plant a vine. The sap starts rising early in grape vines, and any cuts or damage made after about mid-January will bleed quite profusely.

[greenishfing]

I agree totally with ameno. Plant in the ground if at all possible, either inside or outside the greenhouse. You do not need more than one and the vine will give you grapes even if completely neglected (like mine this year) and give you prize winners if looked after minimally. Up here in the cold north I would recommend black Hamberg. Further south you have much more choice.