How big are those pots? If your nasturtiums fried, then Gentians will likely fry too. Your cigar plant certainly will.

Perennial plants can be much tougher to overwinter in pots than in the ground. Pots smaller than 10", or plants that are rated just to your zone will require some sort of extra protection. Depending on what Gentian you have, it might overwinter in a pot on a fence (though I doubt it). The Cuphea won't overwinter anywhere except for inside in a bright window - it's a tropical plant.

In smallish pots that get a lot of sun, plants will generally find it tough to survive. You will need to water every day, sometimes twice a day, and you need to chose your plants with some care. Sempervivums (hens and chicks), Verbena, Celosia, geranium, Coreopsis 'Moonbeam' might be good choices for your pots. Personally I think a wall of hens and chicks would be great, but that's just my preference :-)

I am not a big fan of them, but if you are unable to water every day, you might want to add some water retentive crystals to your potting mix in the future.

As for propagating your Gentian - Gentians tend to be good seed setters. Save any seeds you don't plant right away in the fridge - some gentian seeds have a short shelf life. Cuphea can set seeds, but it is more practical to take small 2-3" cuttings. Strip off the lower leaves, dip the end in some rooting hormone (available at most garden centres), and place it in a pot of dampened perlite or sand ( I find I have better luck rooting cuttings in vermiculite, but you have to be very careful not to overdo the water). Cover with a plastic baggie, and in a few weeks some of them should have rooted. A *very* gentle tug on the cutting will tell you.

BP