I tried last year Hywel. I think it just might possibly work if you start with plants rather than tubers, get off to an early start and are very lucky with the summer. I planted half a dozen plants. I don't think there's much chance of growing from tubers outdoors. My tubers were just beginning to form when the weather put paid to it. They took up quite a lot of space for a nil return but you never know your luck.
You might be better trying them in grow bags in your lean to.

They do need a long, warm to hot growing season, and they don't even try to produce tubers until October, when the days are shorter.

Tug did you mean that they need the shorter days to trigger the growth of tubers?

It seems so. There are probably many day-neutral varieties grown in the tropics, but the ones that I'm familiar with don't bulb up until after the fall equinox.

I tried to grow one as a pot plant for the garden as they are very nice, but I had no idea where to get the plants from, so tried a Tesco tuber - needless to say it didn't work.

Thanks for your replies :) It doesn't sound worth the bother lol We'll continue buying them from the shop.

Cammomile I got my plants from Suttons but you have to buy 6...

Thanks Stera, six would be too many. I saw a beautiful picture of one growing in a large pot and wanted one! It was grown from a tuber but not the supermarket kind as they don't work apparently.

Yes you can grow them from tubers but I believe you have a better chance with plants. For what that's worth...

I grew a few from tubers last year in greenhouse, didn’t get a lot of bother from them but they did take up valuable space and were not v nice to taste after cooking, a bit like sunlight soap.

Hywel - back to the supermarket???

I buy them in the fruit and veg shop :)