Grown in the ground would be better, Grudog, but containers may be possible. Eccremocarpus just don't grow (so the books say - I know of a few that do) in Scotland but we kept one one for several years, up in the north, and only lost it a couple of years ago when the winter was particulary severe. Your problem will be to keep the soil in the pot from freezing rather tan protecting the above ground parts. Can you plunge the pots in winter to even out the soil temperatures?

Hi Grudog, these plants are borderline frost hardy, which means they can withstand temps down to around minus 5 deg c, but being borderline that could be anything from just above freezing, to minus 5, so you wouldn't be able to leave them out all winter.
When you say 9cm, do you mean the plant is 9cm, or the pot is 9cm, if it's the pot then the plant could be very small, {especially if you're thinking of getting them from a company with a 2 name title, 1 beginning with T and the other with M,} personally I wouldn't bother, although you can grow them as an annual, as they're fast growers, Derek.

I have one that survived the winter outside in the border on a free-draining soil. It won't survive on clay as it's too wet. The plant will survive in an unheated greenhouse over winter if you keep it dry and only water sparingly during mild spells (and in the morning to give it time to drink up the water before temps drop at night). It's also easy from seed and will set seed for you to collect, so this is an alternative way to 'keep' the plant from year to year.

many thanks all of you will think about sowing as an annual these were going to come from t m but I wont be getting them now

Good decision!!!!!! Derek.