Hi Rabbit,
When the rose hips are ripe is when they are bright red or more bright orange on some bushes. The hips are like fruit so when they are ripe like an apple, they are good. They do not need to be falling off. The seeds need to be stay moist so the easiest thing to do is keep them in the hips in the fridge until ready to plant. The easiest method of planting is winter sowing. If you don't know about winter sowing, there is a winter sowing forum. Please check it out. So planting them in the next couple months would be the easiest. You can do it indoors, but that to me is more complex. Leaving pots outside is easier, and it works.
Remy

Hi,
Well, I'm a ding bat. I read Confederate Rose and thought of the white rose that grows down south which is Cherokee Rose, lol. So the poster wants to know about Hibiscus mutabilis which of course is completely different than an actual rose.
If the flowers of hibiscus get properly pollinated, a seed pod will develop after the flower petals fall off. Sometimes a seed pod will start, but never make seeds, not sure why. If you get good seed pods, they will turn brown and start to crack open. There will be bb like brown seeds. The pic on the link is a good example.
Remy

Here is a link that might be useful: Hibiscus Seed Pod Photo

Most hibiscus are easy from cuttings. I can't do all plants, but these - easy.