A dog food bag would be about 10 gallons. So 1 or 2 potatoes50 lb dog food bag with drainage holes stabbed in the bottom.
My large containers like that are all black plastic. Not a great idea to my thinking for root veg when the summers regularly stay above 95f/35c for 2-3 months with little rainfall. I can water but that doesn't add humidity to the atmosphere.
Based on the 50 lb of dog food fits into two 5 gallon buckets here.
