The rule of thumb is that the length of canes of a climbing rose will equal 4 times the average of the three dimensions of the pot. So, a pot 70x70x70 cm will grow a rose with canes 280 cm long. The area that that will cover depends on how you train the canes.

Gosh Tug your knowledge never ceases to amaze me. Thats a very useful thing to know.

thanks very much Tug.

In my opinion, roses, especially vigorous ones don't do very well in pots. They like their roots to be cool, continuously moist and lots of room to spread. They are more susceptible to pests and diseases in containers. If it's a sunny spot, then the star jasmine (Trachelospermum jasminoides), would be good or perhaps, pyrancantha (Firethorn) could be trained up a trellis or wires.

Could you take up a paving stone (or whatever your patio is made from) to get the rose in the ground?
I would be wary of putting a climbing rose capable of covering a shed into a pot - certainly not something as small as 70cm - not enough soil to protect against a Northumbrian winter, not enough soil to keep it cool in summer (assuming we get one some time soon), not enough depth for the roots. in a pot it will also need lots of regular watering.

Hi Urbanite, yes I think that's what I'm going to try, it's a sheltered corner that gets plenty of afternoon sun.

If you do not have any great depth of soil after digging up a paving stone use a pot with the base removed. The roots can go further down in to what you have. It is necessary to give the roots a deep run which will allow them to get water even if the surface is frozen.

That's a great idea Scotsgran, thank you.

Does it have to be a rose? An evergreen would be better if you're looking to hide the side of the shed. You could grow an evergreen Clematis cartmanii, for example, which can be grown in a large pot and doesn't get too big. They flower in spring, don't need pruning, and some have fantastic fragrance.

Hi Rosie, my grandad had a beautiful climbing yellow rose bush over his shed, it's sort of stuck with me since I was a kid a long,long time ago, I do love clematis but I was also thinking of honeysuckle too, would that work?