You just need to wait for warmer weather :-) It is too early to plant these in your climate. Wait until close to the last frost date or you can start them in pots indoors slightly earlier, then move them outdoors after all danger of frost has passed. They also grow extremely rapidly from seed, sometimes to the point of being garden pests. But very pretty and relatively easy to control pests :-)

Here is a link that might be useful: growing 4 o'clocks

Thank you for your response, gardengal. Do you think
I will have to dig up the bulbs every year the way a person
does dahlia roots?

Yes, in cold zones (below 8), it is recommended to dig and store over winter much the same as you would dahlias. And save some seed as well. These plants grow very easiy and rapidly from seed, so you'll have a bit of insurance should anything happen to the tubers, like you forget about them :-)

The tubers on these get really huge & can be hard to dig. I'm zone 6 & have a few that have been in ground for about 5 years now & come back fine. It is fairly close to the house & protected from the weather some. I'm curious if it makes it this year though, it is the coldest it has been in years, got down to -4 deg a couple of nights.

I live in zone 7 for the past few years and i have never had to dig up my four o'clocks. They die down every year and come right back the next. I grew up in zone 8 and my mom never dug hers up either. It may be that they reseeded themselves. Good luck!