Will A. curassavica self sow in Zone 6?

[applestar]

The seedpods of Tropical Silky Milkweed (A. curassavica) I grew from seed this spring are starting to split. Does anyone know if they will self-sow/re-seed in Zone 6 or do I need to collect the seeds and start them early in spring again? They were initially very slow growing.

ALSO! I had a conversation with some lovely folks about raising Monarchs earlier this summer. We met at Dr. Douglas Tallamy's lecture about native plants. They questioned the validity of growing tropical milkweed in an area that they are not normally found.

Monarch butterflies would recognize them, certainly, and use the flowers for nectaring and lay eggs (which they have done in my garden). But it is REALLY good for them to do this? The northern Monarchs normally do not have access to curassavica when they migrate this far north. IS it better for them to be raised only on the species that are normally found?

As it is, there are far more A. syriaca in my garden, so they only get a taste of curassavica now and then. I try to distribute them equally -- though in community cages, some will get to eat and others will not. I read that curassavica is more toxic in another thread, so I wonder if it might help them if they get at least some during their development... but there is that natural native range issue.

I need to satisfy myself on this before growing A. curassavica again next spring.

[Mona Miller]

A. curassavica is grown all over the world. It has naturalized in areas along the coast and winters over, but in some places gets killed to the ground.

I'd say in zone 6, that there is a slim chance of it reseeding. I would recommend saving seeds. I'm in zone 7a and it does some times reseed.

You'll also hear the same stuff about butterfly bush.

[applestar]

I realized I forgot to thank you, Mona. So, thank you.

At this point, I'm viewing the A. curassvica and A. physocarpa as excellent nectar source. A. tuberosa is finished and the seedpods are starting to split. But the tropicals are still blooming heavily and Monarchs in the garden regularly visit these flowers.

I've seen eggs and caterpillars on them, but, by far, most of my stock have come from A. syriaca this year. I have been feeding them a small percentage of the tropicals in case the higher toxin level will prove beneficial, and more for these late caterpillars that will definitely be migrating. (I've no idea if this is correct. Just going by gut feeling.... )

As mentioned in another thread, I'll take cuttings and perhaps also try to overwinter some of the full grown plants so they will have a head start as compared to starting them from seed.

[crazymilkweedman]

harvesting the seeds before the birds and mammals eat them is better.99% success rate vs 1-10% germination.
"They questioned the validity of growing tropical milkweed in an area that they are not normally found."
hopefully they mean't "why plant it here if it wont grow here!" Nobody knows the exact historical range of each type..heck they don't even have the current state ranges right..I know..i've found members where they are not supposed to be.
Obviously if it won't survive ..don't plant it ,pick another family member..but i'm pretty sure the Monarchs don't read maps..and so wont say..oh look..curassavica in wherever..wait! that's not native to this area..i better not lay an egg on it!!! LMAO!

[Mona Miller]

Tropical milkweed is an annual in most northern states. I plant it just like I do Cosmos and Zinnias.