Milkweed is the host plant for monarch butterflies. It is the only plant on which they lay eggs and it is the sole food source for their larval form/caterpillars. “Without milkweed, the larva would not be able to develop into a butterfly” (https://www.fs.fed.us/wildflowers/pollinators/Monarch_Butterfly/habitat/index.shtml). Monarchs can thrive with various kinds of milkweeds. Nevada has 17 species of milkweed (USDA NRCS Nevada Plant List). The following are plants frequently used by monarchs here: Asclepias asperula (antelope horns), A. fascicularis (narrowleaf or Mexican whorled milkweed), A. incarnata (swamp milkweed), A. rusbyi ( Rusby’s milkweed) and A. speciosa (showy milkweed). Milkweeds used to be plentiful along pastures and farmers’ fields, but, unfortunately, have been listed in some states as noxious weeds. Thankfully, they are not noxious weeds in Nevada (Nevada Department of Agriculture). The reasoning behind the designation in other states is that some species are toxic to cattle and livestock. Eradicating milkweed eliminates the primary food source for the monarchs, destroying their populations. They are now on the threatened and endangered list. I used to see numbers of monarchs in our yard years ago, but no longer. However, twice recently, I saw three monarchs in south Washoe Valley around clumps of narrowleaf milkweed. Narrowleaf milkweed, with its crown-shaped, greenish-white flowers, likes a dry sunny site (https://plants.usda.gov/DocumentLibrary/plantguide/pdf/cs_asfa.pdf). As named, it has very narrow gray-green leaves. It is a long-lived perennial. Seeds can be sown directly into the ground in the fall. It doesn’t do well in containers. Showy milkweed is an impressive erect plant with balls of white flowers whose nectar feeds a variety of butterflies, bees and other insects. It is slightly toxic to vertebrates. The leaves are large, grayish-green and fuzzy. It too is a long-lived perennial. Showy milkweed is adapted to many soils, as long as there is good drainage. It requires some moisture and won’t tolerate shade. While my plant took three years to bloom, a friend to whom I had given a plant last year had immediate success with blooming and spread. Help increase breeding habitat for monarchs so they can survive. Plant milkweed. The Nevada Monarch Society, based in Reno, is a resource for plants, seed and information (http://nvmonarchs.org/). They recommend waiting for cooler weather to plant. They have 1-gallon or 2-inch pots of narrowleaf or showy milkweed available. They will be hosting an event in October where you can find Monarch Waystation Kits and what you need to turn your yard into monarch habitat. The Greenhouse Project in Carson City (https://www.carsoncitygreenhouse.org/) sells milkweed plants every year at plant sales. Comstock Seed in Gardnerville sells seed. JoAnne Skelly is Associate Professor & Extension Educator Emerita at University of Nevada Cooperative Extension. Email skellyj@unr.edu.
