I would plant them into the ground as soon as they have one or two sets of true leaves. Most milkweed have a long taproot that needs to get established somewhat early to allow the sprout to thrive. So, contact your boss and find out where he wants to plant them and make sure the site is ready.

Martha

I'm sorry I didn't see this sooner, but I have some advice for you: Find a local expert on native plant propagation and learn everything you can about milkweed and pollinator gardening as fast as you can. Pay if you have to. Try Rutgers U. extension service.

You don't say what the mission of your non-profit is, but your BIG donor sent your intimidating (and slightly dense) boss a BIG message: He/she (the donor) is into environmental sustainability and is particularly interested in supporting efforts to restore the health of the imperiled monarch butterfly migratory population of the eastern U.S. There can be no other reason he/she would foist a bunch of milkweed seedpods on your obtuse boss. The donor may continue to contribute to your cause anyway, but if you report back that you've established a huge pollinator garden with lots of milkweed using his/her seeds, and also more milkweed species from other sources, your donor may double, triple, or quadruple the next gift. If you don't respond to the donor's big hint at all, or try to fool him/her with something she recognizes as a hoax, the giving may stop.

Email me at jprice2@wi.rr.com and tell me what you do. If I'm impressed, I will send you several varieties of rare and beautiful milkweeds that will make your donor weep $$$s.