I don't want to turn you off of trying it, it sounds like a lot of people have had success, but I tried for a couple of years to get cascade, hallertauer and nugget to grow in seperate 15 or 20 gallon galvanized trash cans. I cut holes in the bottom for drainage and ground weep holes in the sides and watered regularly but conservatively. The cascades started the year off well but ended up losing vigor. All of them got yellowish spots on the leaves that I at times attributed to nutrient deficiencies and disease. Last year I split off half of each plant and planted it in the ground and they did great -- no discoloration and no fussing. I used good soil in the cans. May be the zinc had something to do with it, although it does not look corroded at all inside. I fertilized from time to time, so I don't think they were starved for nutrients. The root mass becomes pretty large, so for a while I thought may be they just don't like being confined. Any way that was my experience... I planted the remaining rhizomes in the ground a week ago.
If you are limited in space or don't have a better option, then there's nothing to lose. I'm usually good with plants, but may be I just had bad luck with these ones.
First year I planted Cascade, Magnum & Centennial in small planter boxes using Miracle grow potting soil. Cascade grew over 25 feet, Centennial between 15-20 feet and Magnum about 12 feet. The Magnum was battered around by wind storms and damaged but produced the nicest hops of the three. The Cascade produced a lot of hops and the Centennial not too many. Learned a lot the first year and picked the Magnums at the right time, however the other two I picked a bit too early and they were too green/grassy for my taste. Spent $5.00 on a bag of Lady Bugs to control insects and that worked pretty well.
For the upcoming second season they have been transferred into the ground and they have sprouted many shoots so far. Actually think I will be inundated with more hops than I can deal with if the weather is nice this year.
I think container gardening is a great solution if you don't have the space or, for whatever reason, if you just can't put the plants in the ground. Here's my two cents inspired by this forum on growing hops in containers (I think it works good but should be used as a temporary solution if you want the plant to yield it true full potential of beautiful green fat hop cones).
Mine did fine the first year in 25 gal containers. You need to make sure to fertilize regularly. When I pulled the containers inside for the winter I found out the roots actually grew out the holes in the bottom of the container and into the ground. Check my gallery for some pics...
I dont think the root system will stay in the container, especially if you only have a 10-15 gal container...