What can I grow in containers?

I now live in an apt. and I would like to grow some swiss card in a oblong railing planter. Is this possible? Also, I would like to plant some rhubarb. Can I plant a root in a 1 1/2 ft. tub, and if so, would 1 root be enough? I plan on growing herbs also, putting them in pots on my railing. I would appreciate any help anyone can give me--advice is ALWAYS welcome!!

Re : What can I grow in containers?

Maybe just go down the local garden centre and ask for advice on growing rhubarb they will probably know. It tastes nice

I have never grown it in pots / containers, always in the soil.