Posted: 01/11/2016 at 22:15
lilysilly, your instincts are correct
guanajuato is a Very tender variety. it looks like the normal patens varieties but is much taller...mine is 5' tall. you will need to dig it up and treat as you do a dahlia, viz., frost free and dry. It forms tubers. I pot mine into 5 litre pots and keep in conservatory. A gh is prob not warm enough. Pot up using dry mpc. Resist the temptation to water too soon in spring...it is a late starter.
you may have the smaller patens though which are a little hardier but treat just the same as above. It will be bigger and better next year. You can also divide the tubers.