Wow I wasn't expecting so many great replies. Thank you all.
The potatoes were first planted on the bottom can. But within a month it got too big to hold, so I added a second can. Now the plant is over 5 feet high. I'm afraid to add another layer but one of the stems has draped over the can. The time I took this picture was early meaning just about 30 minuets after the first sun peeked out. They normally get a lot of sun here. Not too much though. Watered every day.
I'm glad to FINALLY have some answers. Should I just wait for the plant to die off to harvest since I don't notice flowers??
