Q.Where can I purchase butterfly weed?
I’m searching to buy butterfly weed plants or seeds and am unable to find a source. Can you help me?

Certified GKH Gardening Expert
Butterfly weed (Asclepias tuberosa) is much easier to find now in local nurseries than it was years ago, especially with the plight of diminishing monarchs. The name may be changed so as not to say "weed" but check for the botanical name to be sure.
I have also found that nurseries sell it later in the summer, July and August. You might just ask your local nurseries if they intend to sell it later. Be sure to ask the owner, the summer help might not be aware.
Many online seed companies sell it as well, in seed and flower form. Have you checked with area native plant nurseries and seed companies? Native plants have become more popular in recent years and I'm sure there must be a nursery near you that offers wildlife friendly plants.
There are other milkweed varieties too such as swamp milkweed and common milkweed.
We don't recommend products or brands, so I am not able to give you specific company names, but you may find help at monarchwatch.org, a nonprofit organization.
Here is a link to your county extension office who might be able to help:
https://extension.wsu.edu/okanogan/
Here is a link to an article on our website:
https://www.gardeningknowhow.com/ornamental/flowers/milkweed/growing-butterfly-weed.htm