Wendy it sounds like they need warmer temps to sprout. I've got some incarnata that has sprouted, but 2 other containers haven't and neither has the purple milkweed (A. purpurascens). Caryl, A. syriaca is a wonderful plant, very important host plant for Monarch butterflies, also the flowers have a heavenly fragrance. Otherwise, it is not a great garden plant - it spreads by rhizomes, pretty much where it feels like. I have 3 established patches of it in the yard, all 3 "planted themselves". One of them is in the middle of a woodland garden and it gets very little sun! I've tried transplanting the stalks to another spot, and guess what - it died in the new spot, and came back like gangbusters in the woodland garden.... :-/ Now I let it grow where it wants, and garden around it. It attracts the Monarchs to the yard, and even though the plants growing in shade don't flower, they do provide some handy food for the caterpillars.

Wow! Thank you. Usually when I post on this site, one or more people have to make me feel so small for knowing so little. I'm both thrilled and humbled by how kind and helpful all the responses are. Seriously! Thanks. I actually just went out back to count milkweed plants - 9-10 and all aphid infested to some degree. (Some can be seen from across the yard, some have to be seen close up.) Was surprised to find an oriental one, hidden among the much taller ones. Definitely can't cut down the infested ones, though. lol On the other hand, I forgot some people can actually still see 1/32nd of an inch. That blew me away. I'm impressed. I'm going with, as long as the aphids don't eat butterfly eggs, if I got an egg, eventually, I might see a caterpillar. If I see a caterpillar, the little critter (without touching - bugs give me the hee bee gee bees when they touch me lol) onto the parsley, and hope he doesn't need as much has hubby wants. (Three well-leafed parsleys, so there should be enough for the caterpillar and us. lol) As for seeing monarchs in my garden - nope, not yet. BUT, then again, I actually didn't think there were any butterflies in the city, until the bufferfly bush brought my first Admiral. (Spent five hours online looking up what it was. never saw a red butterfly before - just yellow and orage swallowtails.)If I keep growing the milkweed, sooner or later, a monarch will wander by - maybe. One thing for sure, I've always wanted some ladybugs (found one on one of the milkweeds early on), but didn't think I had enough aphids to feed them. I've since learned how to make a ladybug house, and am working towards gathering the ingredients. I now know I have enough aphids. lol I definitely have parasitic wasp. They like finding cabbage moths on my lavander later in the year. As for hydrating. God's been doing a fine job watering my garden, so far. (I think Philadelphia is getting Settle's rainfall the last couple of months.) Since I'm also growing tomatoes and other produce, I (or God) make sure they get watered daily. Probably why the aphids love them so much. lol So, should my dill get closer to the rest of the butterfly attracting plants? I'm not growing fennel or zinnias. (Am curious which kind of fennel though. I also am getting addicted to herbs. lol) Also, I stumbled upon the offer of milkweed on our local FreeCycle Network, so, like I said, I didn't even know there was such a wide variety. I don't have any more space in my yard to grow more this year, but when do I sow the tropical seeds? I think leaving that container alone last year, allowed the seeds I had to over-winter and sprout naturally. Then again, obviously not tropical. Thanks again for the help. Oh, and since I just looked up tropical milkweed, found an offer for milkweed seeds. They say "free," but they're trying to bring back the monarch after a freeze killed off a whole bunch in Mexico, so let's just say "reasonably priced." The link is below. Here is a link that might be useful: Reasonably priced milkweed seeds

If I had already planted milkweeds grown from seed I'd leave them in place. You have a small enough area that if you wanted to, you could eradicate milkweed pretty easily, or you could control it simply by watching where it comes up each spring and removing the ones you don't want. That is the advantage of a small garden - you can monitor each plant personally, and control the aggressive ones by hand pulling, digging, etc. I would, in future summers, limit the milkweed to maybe 5 or 6 stems. This will be wnough to support a couple of caterpillars, but won't occupy too much space in the garden. You will learn to recognize the new shoots in the spring, and you can pull them up with some of the rhizome that in underneath and i think you'll have OK control.

Here (NJ/Zone 7), the only variety available from local nurseries seems to be Asclepias incarnata (Swamp Milkweek). I just checked a native plant map for this species. It was shown to be native to every state except those on the West Coast..., and Mississippi?i (well, that's odd) This is the first year I am growing them and am interested in adding other species.