Hardy anywhere in Britain below 1,000 feet above sea level.

Is it possible to give a minus number that it can go to.

Thanks.

-15 deg C - as long as its not in soggy soil. Needs full sun

Does it have to have full sun.

If possible, yes, because that means it's south facing, which is better for it in the winter. It'll grow in two thirds sun and a third shade quite happily though.