I've heard these are also hard to start from cuttings, but if I get my hands on some I'll give it a try. Any advise on starting from cuttings is welcome, with any success I'll be happy to share!

~freshair, I just cut a top shoot from a growing plant, about 5-6 inches long, pinch out the growing tip, then remove the leaves on the last one or two leaf nodes nearest the bottom of the cutting. I dip the end going into the potting mix in rooting powder or clonex so that it covers a leaf node going into the potting mix (I'm not certain this is really necessary on this particular plant but couldn't hurt), then stick the cutting into a light dampened mix of Promix (brand name) potting mix and perlite, about 50-50. I've also just stuck the shoots into a small pot of dampened Promix (or any good quality, light potting mix). If there are large leaves on the shoot, either cut the leaves in half or pinch off some of them so the cutting doesn't lose a lot of moisture via the leaf surface. Now set a top half of a 2 liter plastic cola bottle (minus the cap) down over the pot and put them in the shade. Don't let the cuttings dry out. In a week or so you will notice new growth at the exposed leaf node. It is rare for me to have a cutting fail so I figure they are super easy. I mist the cuttings when I think about it but keeping them in the shade until they begin to put out new leaves is very important. Before I had a big butterfly enclosure to raise the little cats in, I'd take shoots from a growing MW, stick them into a block of moistened florist foam and use the MW that way to feed the little cats. They would eat those MW shoots right down to a stalk, even eating part of the stalk. If there were at least two leaf nodes left, I'd stick the lowest leaf node down into potting mix and almost everytime, it would root and grow new leaves from the exposed top leaf node. I've got some pots on my deck right now that have five or six little MW plants in each pot that were started this way. This variety of MW must have some good, strong genes! Give it a try and I think you'll find it very easy to multiply your tropical MW this way. I feel it is probably quicker than starting from seed. I have some tropical MW seed I planted a month ago and there are only two sets of true leaves on these little plants right now. Mary

I guess by now you know that it won't grow from seeds. I'm just wondering how far south it will grow.

I just now noticed my error. I should have asked about C procera as that is the plant I had in mind. I have since discovered Calotropis Gigantea and Calotropis procera are two different plants. Thank you for this helpful information. I think my area gets more cold so I'm not certain I could over winter one here in my greenhouse as I only keep night temps at about 40 degrees through the coldest months. Although if I ever get hold of one of these plants, I'd really like to give it a try. Like Common Milkweed, the size of the leaves are so inviting where garden space is so limited. Common Milkweed usually becomes too ragged here in my garden by late summer to feed the fall migration, as do most of the native milkweeds I grow. May I ask, did you start your plant by seed? My thanks again for taking the time to comment. Mary