It should grow - I rescued mine from a landscaped bed at my son's daycare with not much root attached. It looked pretty unhappy for a little while but I kept watering it and now three years later it is all over my yard.

Be forewarned it travels like crazy, popping up everywhere (including my neighbor's yards). Supposedly Sullivant's Milkweed is better behaved, though I haven't tested that out yet.

The upside is we had lots of Monarch cats last year and the year before and the scent of the flowers is heavenly.

It should be fine. I've dug up common milkweed before and was unable to get all of the tap root, and it still survived. Those roots are pretty deep. Do keep it watered well for the first few weeks. It does spread and can be kind of weedy, but its great for the butterflies - so enjoy.

Thanks, Its raining outside today so no watering. Its looking good. How long before I start to see growth?

It's pretty easy to grow from seed if your plant doesn't live. I used the winter sowing method and got excellent germination. The folks in the butterfly forum could probably supply you with all kinds of milkweed seeds if you ask.
The seed pods stay on for quite awhile before they pop open and fly away so there's enough time to enjoy the flowers and then cut off the pods later to prevent reseeding. I will need to keep mine from reseeding since we have a hayfield nearby and I believe milkweed is poisonous to cattle.
I see common milkweed in ditches all the time but it gets mowed. I didn't realize how big it gets until I saw it planted at my kids school in their butterfly garden. The leaves are huge and it's quite ornamental.

Its doing so so, its leaves are wilted but its not dead yet and I hope it recovers. Gave it water today and wondered if the dead buckthorn stumop that has a strange chem oder to it might be the cause for its weaklness, oh well I hope it covers the stump in time. After you kill a stump with round up how long does the oder last I poured it on full strength because it was so huge, the buckthorn and siberian elm sumps.

I've tried many times, but have never been able to transplant a milkweed.

Please keep us posted.

Any chance the round up migrated from the stumps to your milkweed?

How long ago were those stumps treated?

Be careful what you wish for. Common milkweed will get huge and spread like crazy by underground runners in good soil. For a garden, look for purple milkweed, which is similar but smaller, with but more colorful flowers, and (in my experience) less aggressive.

(update on the milkweed)

Well its the summer of 08 one year after I've rescued the milkweed. Its came up in two large clumps this year one with almost 11 stalks! , I've dug up more milkweed by my dads landscaping to protect it from the lawn maitmense crew he's sent to help our lawn. These I've planted along with the two clumps in the hopes of recreating a milkweed patch. If it gets too wildly invasive I'll dig up clumps and plant at hidden falls river park by my house, not sure of the legalties but it is native and I love helping monarch butterflies.