Thank you Sacha, and all, for your advice and information.
I will plant the seeds this March and, assuming they produce plants,
will post results this summer.
The local garden centers that I called all reported that they propagate
this plant from live cuttings.
Considering this, I wonder how new colors are produced ? From seed I
suspect.
Re what normal weather is like here in Kentucky,
during the last 35 years that we have lived in this Ohio river valley
in the northern part of the state,
the winters of 77-78 bottomed out at -33C and summers frequently top
out at +35 C.
Lake Erie is supposedly one meter deep ,on average,
but I would not attempt to walk across it. (smile)
Regards to all.