Ion Exchange - A company in Harper's Ferry, NE Iowa - (800) 291-2143
native wildflowers and seeds - has milkweed plugs/plants you can order
http://ionxchange.com/search.php?search_query=milkweed&x=0&y=0
http://ionxchange.com
Seed Savers Exchange - Located near Decorah, IA (563) 382-5990
https://www.seedsavers.org
Prairie Moon Nursery - rural Winona County in southeast Minnesota
Monarch Favorites - Nectar Sources and Larval Host Plants
http://www.prairiemoon.com/monarch-favorites/
Prairie Nursery, Westfield, Wisconsin 800-476-9453
https://www.prairienursery.com/
Monarch Watch Milkweed Market
http://monarchwatch.org/milkweed/market/
Monarch Watch: Monarch Waystation Seed kits
http://www.monarchwatch.org/waystations/seed_kit.html
Xerces.org - Milkweed seed finder - Search for where to get seeds
http://www.xerces.org/milkweed-seed-finder/
Swift Greenhouses, Inc - Supplier for Iowa, listed under Monarch Watch as pesticide free - Look for their name/logo on the back of description labels on plants in garden centers.
http://www.swiftgreenhouses.com/