I would stick with Milkweed native to the East Coast. The Monarchs are used to these and are more likely to prefer them over the non natives. A plant outside its natural realm may not preform at its best.
Try Asclepias purpurescens, the Purple Milkweed.
Also, try Swamp Milkweed (A. incarnata) and Common Milkweed (A. syriaca). Poke Milkweed (A. exaltata) likes shadier spots.
Butterfly Weed (A.tuberosa) is the more attractive to the eye and only gets moderate attention from Monarchs and other butterflies.

Vicki,

I live in central Arkansas and like you, admire the beauty of A. cordifolia. However, I can report that I have yet to get even one seed of this MW variety to germinate for me. Might be the seed, my area of the country or simply my lack of skills. The seed was fresh last year, it looked great with big fat middles so I strongly suspect me and or the area where I live.

A. cordifolia does make a stunning plant. Perhaps someone else will chime in with their experience in trying to grow this variety of milkweed outside of it's native area.

You might want to ask your question over in the Milkweed forum, too.

Mary

I started A speciosa from seed about 3 years ago. Got 2 seedlings, planted them in a well-drained bed, and the plants have barely thrived. They might have died last summer, not sure. I could try transplanting them, but Asclepias is a fussy species and I've not had any luck transplanting mature A syriaca which is similar.

In general, I've had limited success growing western natives in the eastern US. I think our climate is too wet, and possibly the soil is more acidic, and perhaps other factors?

YMMV. Why not try? I love to experiment. But if you have limited space, I would grow A. incarnata or A. curassavica (some controversy over this one). I think they are both pretty milkweeds and they are very attractive to female Monarchs and used frequently as host plants in my gardens.

A. cordifolia was not a name I recognized. Now I know why. It is not a species that gets used for research. You have to go back to the '70s to find people using it. Don't know why. What I did find is the cardenolide content of A. cordifolia is just barely higher than A. syriaca. Unfortunately, that info by itself means little.

A. speciosa is pretty much at the bottom when it comes to lifespan of non-migrating monarchs. Common, purple, and swamp are at the top. A. speciosa averages 25 days while A. incarnata is 34 days.

KC

Good facts to know, KC.
Common, Purple and Swamp are at the forefront of my Monarch patches. I also have some tuberosa and some Oscar, but the jury's still out on the latter until I know better what survived Winter this year.
I tried growing speciosa and exaltata at one point, but the rabbits just made a meal out of them.

Hi KC,

what are the adult butterflies fed in these studies? Tony

Tony,
In the study I was referencing, they were not fed anything. Each individual was kept in a separate envelope at 12 C and checked daily for death. Previous studies have shown that this way emulates monarchs that were fed in natural conditions. Takes some variables out of the equation so the results are tougher to attack.

The sited previous studies are:

De Roode, J. C., A. J. Yates, and S. Altizer. 2008b. Virulence-transmission trade-offs and population divergence in virulence in a naturally occurring butterfly parasite. Proc. Natl. Acad. Sci. USA 105:7489-7494.

De Roode, J. C., J. Chi, R. M. Rarick, and S. Altizer. 2009. Strength in numbers: high parasite burdens increase transmission of a protozoan parasite of monarch butterflies (Danaus plexippus). Oecologia 161:67-75.

KC

Here is a link that might be useful: FOOD PLANT DERIVED DISEASE TOLERANCE AND RESISTANCE IN A NATURAL BUTTERFLY-PLANT-PARASITE INTERACTIONS