I've had lovely blooms on my jackmanii since...well, I don't remember exactly, but it seems like since June. Now, the blooms have all died out and new ones haven't replaced them. I only watered them a couple of times this summer, despite the fact that it's been somewhat dry. (Here in Massachusetts, it's dry, but not a drought.) Should I have watered them more? Fed them more? Or is it "normal" for them to stop blooming around now? (I had heard they would bloom through September.)
Two of my three Jackmanii clem's have almost stopped producing flowers - maybe it's the heat. You can water them more often, deeply - not often, and give them some rose or tomato food as long as they don't have buds. Make sure you have them well mulched. By September you should get more blooms.
Jackmanii and many others can be raised in pots. They just require more care, more water and more food since the nutrients wash through a pot faster than if they were in the ground. I wouldn't recommend pot culture for any of the Class/group/type 1's. I doubt a Jackmanii in a pot can grow to the size of yours, onegoodman.