Zone hardiness ratings are based on mature plants, not on seedlings, and they are generally root hardiness at that. In other words, the plant could die to the ground, but the roots remain healthy (although dormant) enough to make it through winter. I've seen 'Moy Grande' listed for 5 and 6, but again, that's a mature specimen. Hibiscus has incredibly large root systems, because they are voracious feeders with large canopies to support. A seedling wouldn't have nearly as much root mass, so it would be more apt to be bothered by cold.

I have one of these and have grown a couple from seed. Mine are in moist but not wet rich soil, which is where any hibiscus will do well; it's not as large as the one in the NC Botanical Garden but it's about 4 feet tall. I don't know if they can live happily in standing water like H. coccineus and moscheutos or not. Germination of the seed was also like other hibsicus; I don't usually bother to nick or soak the seed although this can speed up germination; I just sow outside in pots in early and let the heat and rain soften and swell the seeds.

olyagrove, tooooo funny about taking them to the swap and little interest was shown. I've done that myself. About five years ago, someone gave me a plant. Didn't know what it was; wasn't that interested, and it barely survived. I mean BARELY, because I completely neglected it. So this past winter, I finally take a picture and post it on the succulent website. Turns out, it is an orchid cactus (epiphyllum). After I saw the pictures of others in bloom, my attitude became "WOW! How cool!" Now I am loving this little stepchild, nurturing him along and hoping he will bloom. Take seedlings to the next swap and I bet they will be more popular now. :) Here is a link that might be useful: Images of blooming orchid cactus - if you are interested

Susan, Sorry not to get back with you sooner...I was out of town. I think you nailed it with the H. dasycalyx! Not 100% sure, but if it's not, it's darn close! I've got lots of seeds, though! I had taken a couple of seed pods, then caught my 11 yo dd over there gathering handfuls of pods! LOL! She told me we had to have this hibiscus in our yard. Isn't that great?? I told her not to take too many-she'd strip it if I've let her! Now I've just got to clean them up. I also picked up some honeyball bush ball-things, but I'm not sure exactly what part are the seeds. Got any ideas? They almost look like dried up monarda heads, but smaller. And they come apart like gaillarda. I think that part is the seeds. But, I want to be sure. HW