In my most recent batch of Asclepias curassavica seeds sown in a flat, they all popped up simultaneously on day 5, thick as a little green lawn:-) On the same day, Sept. 19th, I sowed seeds of Asclepias viridis from Randy (sorry, I forgot his Gardenweb nickname) [Thanks, Randy!] and Asclepias verticillata that I bought last year. I'll report when they come up. Okay, that was a nice break, now back outside to pull weeds again...

Hey. I was researching Milkweed seeds yesterday and found a site with all the various ones and they listed which needed stratification and which didn't. I did the search on another computer so I don't have the site here, but I think I searched for "Milkweed Seeds" from Google. I will try to get it tomorrow and post it here if time permits and if I remember. I'm trying to root stems of mine and not having very much luck.

Found one of the sites that shows which seeds need what... http://www.butterflyencounters.com/store/products.php

I use a rooting powder and have had good luck with stem cuttings of A. curassavica and A. incarnata.

Tee-hee! I live in a rather dry climate so it takes a bit MORE help to get 'em going, I guess. ;P Having a mini hothouse would probably have you with 'Jack and the beanstalk-type' Milkweed! LOL (or mold, right? yuck)

I have planted A. californica and that took a lot longer to germinate for me when compared to the A. curassavica. I think it was a good two weeks+.

Milkweed seeds always take a long time for me, but that's probably because I'm always trying to start them when it's too cold. A. curassavica and A. tuberosa take two to three weeks, and A. perennis takes a minimum of a month. But once they come up, they do fine, although they don't seem as strong as the ones that germinate outside from seeds that escaped the previous season. I've never been able to get A. syriaca or A. incarnata to germinate at all.

Thanks for that website, Liljagster!

Geni, I've had both good luck and zero luck with A. incarnata.

The A. verticillata and A. viridis seeds I mentioned planting on this thread on Sept. 19th have only yielded two sprouts, a couple of days ago. They were both Asclepias verticillata. I'll just leave the flats of seeds through the winter and water them well in the spring. As for the A. verticillata, I stratified it in my refrigerator in water the first time I sowed them and that time I had good success. I got the following instructions from another forum (it's the Yahoo group growingnative) Here's what Rufino Osorio wrote a year or two ago when asked about Asclepias perennis seeds:
"I left the seeds in the refrigerator about 3.5 weeks and replaced the water about once a week with fresh cold water. This method has proven quite effective at breaking the dormancy of a very wide variety of Asclepias species."
I haven't found the original post, but he had already explained that he was letting the seeds soak entirely in water for the 3.5 week treatment. He said 4 weeks was equally successful, too, so 3.5 isn't a magic number.

That's pretty much my experience with A. perennis -- keep them wet and cold for a month and they'll all come up. I've done it in February-March in a potting shed instead of the refrigerator, but it's the same effect -- up here anyway. Just dumb luck. I had always figured they took so long because the temperature was too low.

The A. perennis is blooming again. It recovered after the Monarchs stopped ovipositing. I was able to collect a few seedpods from the bare sticks in September. Not as many as last year, but thanks to your gentle counsel, the seeds should survive mailing this year if you or anyone else wants any. I'm wrapping them in bubblewrap and enclosing that in a padded mailer. (Last year I sent Carol some in a plain, flat envelope and they arrived as powder.)
g.

I purchased Milkweed seed from www.butterflyencounters.com

Pulchra Swamp Milkweed Seed:
Asclepias incarnata spp. pulchra

Swamp Milkweed Seed:
Asclepias incarnata 'Ice Ballet'

Prairie Milkweed Seed:
Asclepias sullivantii

the planting instructions on the packets are as follows:

all of these require stratification:

START seeds outdoors in fall or ...

Put seeds in an air tight container filled with moist sand and store in the refrigerator for 6-8 weeks before planting.

plant seeds about 1/8 inch deep in a soil with good drainage. A mixture with peat moss, sand, and perlite works very well. Keep soil moist until the plants reach a height of 6 inches.

Germination can take anywhere from 10 - 20 days.

Mary

I've been growing milkweed for about 6 years. I've decided that there are many variables that are hard to account for. I primarily wintersow or direct sow, and each year is different. I always use Miracle Grow seed mix (habit and availability) and winter sow some time in mid winter, but some years I have great success with one type and none with another. The next year, everything does well. I collect all my own seeds in late fall. So, I think we're all subject to the mysteries of mother nature and the unique circumstances of our particular microclimates. Happily, this year was a bumper year for me. I have more milkweed sprouts than I know what to do with. And when I went out to plant some, I found a bumper crop of volunteers. It probably helps to have an established population dropping vast numbers of seeds. Now I just hope the butterflies find me. I have a smallish yard surrounded by tall trees, so I'm not easily spotted from up above.

Martha