There are some roses that work better in pots than others. The large
Grandiflora is a bad choice for pots because it is huge. There are tons
of fairie roses that grow great in pots and bloom profusely. A simple
12 inch pot will do and you do NOT have to have special rose soil. But,
roses grow best in sandy loam, so if you have only top soil, throw some
sand and peat in with the mix in the pot. The type of pot you get
depends on how fast it will dry out. I am in Texas, which means my
roses in pots would barely last a day in the summer if I had them in
terracotta pots. To keep water in, they have to be plastic or glazed
pottery. But, as you are in Wisconsin, your probably would be more in
the blackspot/mildew family, I am guessing.

Does that help?