Four o'clocks, never dug the tuber just happen to be in the same pot as some cannas and salvia I brought in the basement. Mine were much larger than last year. I think you can dig them and wrap them in paper and store in a box like dahlias, just make sure they don't dry out and aren't soaking wet either. I had red ones one year that came back all over from seed the following spring. I'm going to toss some in in the fall this year and see what happens.
My evolvulus does way better in some shade. As for the heat, it's not really that, they are related to morning glories and start to bloom better when the days become shorter they will be gangbusters next month.
