Here’s the bad news: The monarch butterfly population has decreased by 90% over the last 20 years, mostly due to agriculture and gardening practices, and destruction of America’s grasslands. The good news (you knew we wouldn’t leave you hanging in despair) is that there is something you can do about it — plant milkweed! The milkweed plant is the only host plant for the monarch caterpillar, and without it, this gorgeous butterfly can’t successfully reproduce. While there are over 70 varieties of native milkweed, we’ve chosen our top 5 milkweed varieties according to their appeal to both coasts of the United States, and because of their non-invasive or weedy status.
1. Swamp milkweed (Asclepias incarnata). Also known as pink milkweed for its clusters of small rose-purple flowers, this plant grows 2-5’ tall, blooms from June-October, tolerates shade, and prefers moist to wet soil.
Native range: AL, AR, CO, CT, DC, DE, FL, GA, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, PA, RI, SC, SD, TN, TX, UT, VA, VT, WI, WV, WY
2. Showy milkweed (Asclepias speciosa). This milkweed has clusters of rose-colored flowers from May-September and grows up to 3’ tall (6’ tall if it is really happy). Give it a lot of sun and moist soil for best results.
Native range: AZ, CA, CO, IA, ID, IL, KS, MI, MN, MT, ND, NE, NM, NV, OK, OR, SD, TX, UT, WA, WI, WY
3. Common milkweed (Asclepias syriaca). While usually reaching heights of 3-5’, common milkweed will grow up to 8’ tall in moist ditches. It features large spheres of pink-purple flowers and likes plenty of sun and water.
Native range: AL, AR, CT, DC, DE, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, VA, VT, WI, WV
4. Broadleaf milkweed (Asclepias latifolia). While this milkweed is not one of the showiest, it has value beyond mere appearances. It has broad, large leaves and pale green-yellow flowers tucked into the foliage in late summer to early fall. However, this one does well in drier soils, making it very sought-after in its native range.
Native range: of AZ, CA, CO, KS, NE, NM, OK, SD, TX, and UT
5. Antelope horns milkweed (Asclepias asperula). This shorter milkweed grows up to 2’ tall but has uniquely interesting features. It has maroon-tinged, greenish-yellow flowers and seed pods that arch to resemble antelope horns. Give it sun and medium water.
Native range: AZ, CA, CO, ID, KS, NE, NM, NV, OK, TX, UT
Tip: We have to mention Butterfly milkweed (A. tuberosa) — named the Perennial of the Year for 2017, this showy plant has orange-yellow or bright orange flowers from May – September and is one of the pretties milkweeds around. However, monarchs won’t make regular use of this plant unless it is the only milkweed variety available.
Native range: AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, NE, NH, NJ, NM, NY, OH, OK, PA, RI, SC, SD, TN, TX, UT, VA, VT, WI, WV