Plants are divided into these groups: Perennials (those that return in return in the same spot you plant in year after year) Annuals (those that complete their life cycle in one year) and include: Hardy annuals thrive in cool weather and are usually planted in the fall. Half-hardy annuals can endure light frost; they are generally planted in early spring. Tender annuals die in freezing temperatures and are planted in the spring. Zinnias are tender annuals, and seeds should be planted after the last frost in your zone. Most, but not all, perennial seeds need a period of vernalization, or cold stratification, in order to break the seeds' dormancy. Most milkweeds grown in the U.S. are native to the U.S. and are of this type. Other the milkweeds may be perennial in warmer or more tropical zones, don't need to be stratified, and are grown as annuals from zone 8, sometimes 7, north (depending on our winters), including Tropical Milkweed (Asclepias curassavica), Oscar Milkweed (Asclepias physocarpa), and a few others. In your zone, these may grow year-round. Asclepias fasicularis or Narrow-leaved milkweed, is a perennial milkweed native to the Western U.S. I hope someone from that area will come in an help us out on that milkweed in particular. I don't grow it in my garden because it is a Western native. Perennial milkweeds usually require at least 30 days of cold stratification. You can "winter sow" them - check out the Winter Sowing Forum here; you can stratify them in a baggy containing 1/4 cup of sand, 1 tsp water, in the fridge), remove them after 30 days minimal, and plant them in pots. Sandy is quite knowledgeable on this method and she can help us out in this regard. I usually winter sow mine recycled 2 litre soda bottles. Perennials, from seed, usually follow this pattern: 1st year they sleep, 2nd year they creep, and 3 year they leap. So it can be 3 (2 at a minimum) years before you see significant growth and flowering in perennial milkweeds. Other perennial milkweeds you might want to consider growing in your area include six that are commercially available (some harder to find than others), Asclepias californica, A. speciosa (I grow this one as it is native in Oklahoma as well), A. fasicularis (Narrow-leaved Milkweed), A. cordifolia (Heart-Leaf Milkweed), A. vestita (Wooly Milkweed), A. eriocarpa (Woolypod Milkweed). That said, A. speciosa and A. fascularis are the most common that I see folks growing on this forum. I think that A. cordifolia is a beautiful milkweed, in particular, with its purple flowers. I have seen seeds offered for sale of all of these milkweeds, though. Nine other milkweeds, for a total of fifteen, are native to California, but only these six are generally found to be for sale (seeds and/or plants). If you have a native plant nursery in your area, or know of native plant societies or groups in your area of California that may have annual plant sales - I know it's a huge state - you might try to find out where you can locate plants, if you are interested. Plants will obviously give you a jump start over seeds. Those warmer climate milkweeds like the Tropical, Oscar, or Giant Milkweeds will grow quickly and bloom for you in one season. You can collect seeds to keep your collection going of these. In your zone 9, I'm not sure what temps you're experiencing now, as to whether you can start seeds now outdoors. I'm hoping someone else can supplement this post that has experience gardening in California in your zone. Larry_Gene may have some additional info for you. Try googling "Butterfly Encounters milkweed seeds" and check out the milkweeds they offer. They are an excellent source of viable seeds. In regard to Zinnias, most are attractive to butterflies. I prefer sticking to the single flowering varieties that afford a flat landing pad for the butterfly. Some I am looking at for planting this year include the Whirligigs/Carousel, Chippendale, Profusion singles, Cut & Come Again mix, Zahara series, Sombrero, Old Mexico. Some of these are mixes that will produce both single and double flowers. If you go to the Annuals forum, there is a lot of discussion on various types of Zinnias on the market. I am going to order a lot from Hazzard's Seeds (go to their site and use the search function for "Zinnia" and you'll get a listing of all their Zinnias). They are wholesale, but will sell retail. For instance, I can get 1,000 Whirligig's for $6.55. I can 1,000 of the Sombreros for $5.10. That is CHEAP! Some of the seeds are more expensive, but there are a lot of varieties you can buy in large numbers for very, very reasonable prices compared to the seed numbers you get from other places. Have fun! Susan Here is a link that might be useful: Milkweed Seeds

Dear Mechelle - I live in the Tidewater area of Eastern Virginia out near Williamsburg, and am desperately trying to farm Aritolochias to raise PVS cats also, as are many other people. If you have any fimbriata seeds still available at this late date, I would love to have a few and give them a try. I'm afraid I don't know much about raising the very small serpentaria roots that I recently purchased. But they are potted up and show signs of growth, even in now in August. The seller said that they wouldn't grow until next Spring, which kinda surprised me! So I've been online reading on the Forum here and I've learned that having "back-up" forage plants is a must when one has a female PVS visitor, which I plan for next Spring. Can you help? Do you have suggestions for keeping serpentaria "vines" alive until next Spring in zone 7? I could even send you an SASE to make it easy (if you have any fimbriata seeds still available)! Thanks!

The dionae and drosera palacea and burmanii don't need a cold strat. The ceph needs a dry cold strat for 8 weeks. The sarracenia and cobra need a 4-6 week cold strat. Not sure about sessifolia but iinm it doesnt need a strat either.

I'm trying an experiment, in general. I am going on the premise that temperate plants, such as Sarracenias, Darlingtonia, a few Drosera, and a N.A. Pinguicula seeds land in some semblence of cold water and go through a stratification process. Then, as photoperiod and temps increase, they naturally germinate. So... I am attemptiing just that, with several Sarracenias, D. filiformis, Cobra Lily, P. vulgaris, and P. grandiflora. I filled plastic drinking cups partially with media and overfilled with rainwater. Then I poured the seeds. The Sarracenia seeds very obviously floated. Hard to tell with the others. I am keeping them uncovered, in my cold attic, by a SE window sill. We'll see what happens!