Where Are The Monarchs?

Seeing any orange and black flappers this year? No? Not too many? Those giant monarch clusters…not so big? Not surprising. The monarch in Southern California has been experiencing dramatically depleted populations and last year was no exception.

Every year around Thanksgiving, scores of citizen scientists – under the guidance of the Xerces Society – head out into the known over-wintering sites of the monarch butterfly. There are 19 sites in Los Angeles County, 10 in Ventura, 16 for Orange County and a whopping 50 in Santa Barbara County.

Volunteers carefully count, track and record the numbers of the orange and black beauties that hang in large clusters –usually on eucalyptus trees – for warmth and safety.

With not all the data completely tallied, Xerces officials estimate that numbers for 2012 monarchs are down from the previous year, but it’s hard to exactly say by how much.

What is known, however, is that butterfly populations are down 85 percent since volunteers have been monitoring the sites 16 years ago. It’s been a steady steep drop-off since 1998 with slight ups and downs throughout the years. It’s an even scarier fact in graph form.

Graph provided by The Xerces Society; Western Monarch Thanksgiving Count data from Monroe, Frey and Stevens 2012
Graph provided by The Xerces Society; Western Monarch Thanksgiving Count data from Monroe, Frey and Stevens 2012

“Loss of habitat is the big issue,” says Sarina Jepsen, Endangered Species Program Director.  “Monarchs need milkweed and so much of that native plant is gone. I’ve also seen numbers of [monarch] sites come into development and completely destroy those wintering sites. It continues to happen today.”

The monarch is a somewhat mysterious creature in Southern California – no one knows exactly which groups of monarchs we have here hanging in our trees or flittering in the skies.

More than likely, says Jepsen, many of our monarchs migrate from the Western U.S. to our coastlines, although tagging has revealed some Mexican monarchs coming here for winter as well. To make matters more confusing, some California monarchs head down to Mexico for the winter months. “There’s a lot of mixing going on,” admits Jepsen. Call SoCal the veritable monarch melting pot.

Going hand in hand with habitat destruction for the monarch, is loss of native milkweed, the preferred plant of choice for discerning monarchs everywhere.

Milkweeds, just like monarchs, are multi-layered and highly specialized for its particular climate and terrain. In fact, according to Brianna Border, Plant Ecologist at Xerces, California alone has 15 species of native milkweed – and that’s not counting that flashy intruder, the exotic A. curassavica, tropical milkweed (also known as blood flower or Mexican milkweed) that’s the bugaboo for Lepidoptera scientists.


Some argue that the plant – which can be readily found at any well-stocked SoCal nursery – is so hardy that it doesn’t die back in the cold winters, meaning that monarchs think it’s time to lay eggs outside of their regular breeding season. Their natural cycle gets messed up and…you can guess the rest. Plus, a parasite has been known to build up on these “never die back” milkweed plants which is then transmitted to caterpillars and…you can guess the rest.

The solution says Border is found with native milkweeds, and Xerces is promoting its Project Milkweed with California as one of six states to be targeted. The project aims to make appropriate native milkweed available for large scale restoration efforts, and eventually the local gardener. The project also wants to raise public awareness about monarchs and build new markets for milkweed seed within the native seed industry.

“Commercial sources of locally native milkweed seed are scarce,” says Border who admits that currently native seeds are being produced in California’s Central Valley – but not ideal seeds for us in SoCal Land. She does list local SoCal nurseries that *do* carry native milkweeds.

Grow Native Nursery, affiliated with the Rancho Santa Ana Botanic Garden, and with locations in Claremont and Westwood, sells Asclepias fascicularis and A. speciosa

Laspilitas Nursery, located in Escondido: (though their website usually implies that they have numerous milkweed plants in production that are not yet ready for sale/shipping)

Moosa Creek Nursery, in Valley Center, sells Asclepias fascicularis and A. speciosa

Recon Native Plants, in San Diego, sells A. californica and A. speciosa (wholesale only):

Tree of Life Nursery, in San Juan Capistrano, sells A. speciosa

Nopalito Native Plant Nursery, LLC, in Ventura, sells A. fascicularis:

 *Note: Asclepias speciosa is not actually native to the southernmost ~1/3 of the state, but it’s a beautiful plant and I’m not surprised to see that nurseries are offering it. I don’t see any problem with people planting it in gardens, but it wouldn’t be my top recommendation for planting in natural areas of Southern CA.

 Planting local milkweed is a 2-for-1 endeavor says Border because “not only will the plant support monarchs, but a host of other pollinators including native bees and other beneficial insects.”


With clusters of delicate flowers, we think the plant will definitely boost the beauty-quota level of any back, front or side garden.Course, that native milkweed will look all the more lovely when a gentle orange and black monarch lands on it.

Gardeners, start your troweling…

— Brenda Rees, editor