Minimum soil required

Plan on getting Pro Mix HP and some chicken manure.

Question is, what is the minimum amount of soil required for an outdoor grow? Is 2 gallon buckets enough?

Thanks

if your only going to use a 2 gal. pot, you will have a short, stunted plant. can do, but not a big return maybe 1/2oz. if your lucky. alot of grow threads use different size containers from 16oz. drinking cups to 55gal. drums, its all good.

Put the plant in the ground.