Native milkweeds (Asclepias spp.) are essential for monarch butterfly (Danaus plexippus) caterpillars and support a diversity of pollinators with their abundant nectar. By including milkweeds in gardens, landscaping, wildlife habitat restoration projects, and native revegetation efforts, you can provide breeding habitat for monarchs as well as a valuable nectar source for butterflies, bees, and other beneficial insects. As part of our Project Milkweed, we have created this comprehensive national directory of milkweed seed vendors to help you find sources of seed. To learn more about monarch butterflies and how you can participate in conservation efforts, please visit the Xerces Society’s Monarch Butterfly Conservation page or the Monarch Joint Venture webpage.
We also advise you to read the important considerations detailed here:
At present, nearly 40 milkweed species are available as seed to varying degrees, although availability varies widely by region. Through Project Milkweed, we have been working to change this in several states, but notable gaps in availability remain.
In addition to seed, several nurseries also sell milkweed transplants (“plugs”). Please ask your regional vendors about availability. For regional lists of native plant nurseries, visit our Pollinator Conservation Resource Center.
We encourage you to only plant milkweed species that are native to your area. The Biota of North America Program’s (BONAP) web-based North American Plant Atlas provides county-level distribution information for all Asclepias species in the lower 48 states (milkweeds are not native to Alaska and Hawaii). Please refer to BONAP’s map color key for detailed information, and note that dark green indicates that the species is present within the state, while bright green shows that the species is documented to occur in that specific county. However, these maps do not convey the abundance of the species within each county.
For recommendations of which species to plant on a regional basis please download this fact sheet by the Monarch Joint Venture.
Three Asclepias species have been introduced to the United States: tropical milkweed (A. curassavica), African milkweed (A. fruticosa), and swan or balloon plant (A. physocarpa). Of these, tropical milkweed (also called blood flower or scarlet milkweed) is the most widely available from commercial sources. However, there is preliminary evidence that where tropical milkweed has been introduced, its presence may cause monarchs to reproduce outside of their regular breeding season, disrupt monarchs’ migratory cycle, and increase transmission and virulence of the protozoan parasite (Ophryocystis elektroscirrha). Thus, some monarch scientists are concerned that the planting of tropical milkweed may lead to negative impacts on monarch health. For more information on this topic, please download this fact sheet by the Monarch Joint Venture or read this Q&A, also from the Monarch Joint Venture, about research related to tropical milkweed and monarch parasites.
An ecologically responsible approach is to use seed that is sourced as locally to your property or project site as possible. Milkweed seed can be purchased on the internet from multiple vendors but given some species’ broad distribution across the United States, available seed may be of non-local origin. While some seed companies specialize in locally native seed, many do not advertise seed origin or ecotype, and it should not be assumed that seeds have been collected or produced in the region in which a vendor is located. To identify sources of regionally appropriate seed, please ask prospective vendors for information about seed origin. If milkweed seed is completely unavailable within your region, yet milkweeds are integral to your planting plans, you could consider making arrangements to have seed wild-collected from local populations.
Successfully establishing milkweed requires some very specific steps. Please refer to our Project Milkweed page for more information on successful milkweed establishment. For those working to Save Western Monarchs by planting milkweed in California, please refer to our fact sheet Native Milkweed in California: Planting and Establishment.
If you are a milkweed vendor and would like to either be added to this directory or to make changes to your vendor entry, please submit a vendor interest form for your business, organization, or network.