My mother used to grow them in your zone. However, she planted them at the end of March and already had "put up" most of them by now in jars for the winter months. I am not sure about the heat, but the humidity had something to do with it. Did the same with butter beans---yummy, I can still taste those..
Coleen

I had some in my front garden, but I pulled it out because the tendrils were wrapping around all the other plants and I forgot to replant it, so now it's gone. It had cute little red flowers on it. It did well in the heat, but I'm not sure about the winter.
Annie

Well, mine are up the trellis about 18" but the slugs(shell-less snails) are working on the bottom leaves. Normally this is not a problem but with the continuous rain, it's a problem now.