I've just been realizing that I'm not seeing any monarchs where I live! And with that, I realize too that I've not seen any milkweed around. We live in a self-contained golf community, with homes built around the fairway. The only "wild" areas are lots that haven't sold and are undeveloped, of which I'm glad to say there are three across the street from us. Some people would consider them messy but I'm enjoying the weeds and trees that will be cut when and if someone buys the property! But I have yet to see any milkweed there, or anywhere else around here. Does that mean I won't be seeing any monarchs? If I were to plant some asclepias tuberosa next year, might that be enough to entice them to stop by? This is upsetting, we always had tons of monarchs back in CT, but we also had lots of meadowland, full of milkweed. Hate to think of what will happen as those meadowlands continue to be turned into concrete jungles....
Lack of monarchs in my area
thea--I do not know much about the South Carolina butterfly population either, but I do know that monarchs have 'flights' throughout the fair weather seasons when they are more common because of migratory habits and egg laying habits.
The Journey North site may give you some detail about your area and you will be able to compare it to your CT home, also. http://www.learner.org/jnorth/monarch/index.html
The butterflies like my Asclepias turberosa and other milkweeds and native nectar plants are relatively easy to grow from seed, too. You can probably starts some milkweed seedlings right now or throw out collected seed onto the vacant lots in the spring, or even start cuttings from established milkweed. Here is a link to some milkweed propagation information for the details: http://monarchwatch.org/milkweed/prop.htm
Joe Pye Weed and Iron Weed are two other native style plants that the Monarchs like that might work on the lots. In your own patio or yard in addition to the asclepias tuberosa you might try containers of zinnias, tithonia and sedum for the butterflies if you aren't keeping a garden, per se. And I like asclepias curassavica, too. It's treated as an annual in Zone 6, but it is easy to start from cuttings.
http://www.hiltonpond.org/ResearchMonarchHelpMain.html
Good luck!