Archives For monarch butterfly

Want to help monarch butterflies? Be careful when selecting your milkweed. Not all plants that go by the common name of “milkweed” are the food that these butterflies need. 

Want to save the monarch butterfly? Plant milkweed. Pick up a free milkweed seedling at World Environment Day this Saturday, June 4.

Danaus plexippus (Monarch) egg on the underside of a leaf.

Danaus plexippus (Monarch) egg on the underside of a leaf. Photo by Bfpage [CC BY-SA 4.0], via Wikimedia Commons

Milkweed is both a food source and a host plant on which the monarch butterflies lay their eggs. Monarchs lay their eggs on the underside of the milkweed foliage.

After hatching, the larvae consume the foliage, which is high in cardiac glycosides—a poison that interferes with the heart functioning of vertebrates (animals with a skeleton). Butterflies are insects with an exoskeleton, and so are not affected by the toxin.

Within the Chicago region, the following milkweed species (Asclepias) are native:

  • Asclepias amplexicaulis is native to our prairies and is suitable for planting in sunny perennial flower gardens. The flowers are described as “eraser pink” in color and are fragrant (honey).
  • Asclepias exaltata is native to our woodlands and is suitable for planting in partially shaded gardens. The flowers are white and also fragrant.
  • Asclepias incarnata is native to both prairie and woodlands and can be planted in a variety of garden locations. The flowers are pink and fragrant. Gardeners may also be interested in three cultivars of this species:
    • ‘Cinderella’ has light and medium pink flowers
    • ‘Ice Ballet’ has white flowers
    • ‘Soulmate’ has medium and dark pink flowers
  • Asclepias tuberosa goes by the common name of Butterfly Weed. It features bright gold and orange flowers—and is fragrant. A native of sunny prairies, it also has cultivars that have been selected for specific colors:
    • ‘Hello Yellow’
    • ‘Western Gold Mix’
    • ‘Gay Butterflies’ (orange, red, yellow)
  • Asclepias purpurascens has fragrant pinkish-purple flowers and can tolerate both sun and shade locations in the home landscape.

Cultivars may be easier to find in your local garden center or nursery, but specialist nurseries do carry both potted plants as well as seeds.

Asclepias syriaca

Asclepias syriaca

Asclepias tuberosa

Asclepias tuberosa

Download the Chicago Botanic Garden Milkweed Map and take a tour of our native milkweeds.

The Bad Seeds

The bad actors, unfortunately, also go by the common name of milkweed, and are in the same plant family but a different genus: Cynanchum. Three species are reported in the upper Midwest and should not be planted by gardeners. All have fragrant flowers and wind-dispersed seeds:

  • Cynanchum louiseae goes by the name of Louise’s swallow wort, or milkweed. It is native to southeastern Europe.
  • Cynanchum louiseae goes by the name of European swallow wort or milkweed. It is native to southern Europe.
  • Cynanchum vincetoxicum goes by the name of white swallow wort or milkweed. It is native to Europe and Asia.

So, why will monarch larvae die on the wrong milkweed? 

Hmmm, perhaps an illustration. Both mango and poison ivy are in the same plant family (Anacardiaceae) and contain similar biologically active compounds. My daughter and I can’t get enough mango in our diet, but both break out in poison ivy rashes if we touch poison ivy plants. The compounds are similar but not exactly the same.

Likewise with the “bad” and “good” milkweeds: Both have fragrant flowers, the flower shapes are similar, the leaf shapes are similar, both have milky sap. But there is an insecticide compound in the “bad” milkweed in addition to the cardiac glycoside.

“Bad” milkweeds evolved in Europe, where there are no native monarch butterflies, but plenty of herbivores, both animal and insect. “Good” milkweeds evolved in North America in conjunction with monarch butterflies.

Monarch caterpillar

Monarch caterpillar

Somehow, the monarch larvae are able to ingest and retain cardiac glycosides in their tissues without dying. It is a very unique adaptation between these two species. If other species of butterflies were to lay their eggs on milkweed, the larvae would not survive. Each organism has these sorts of “monarch-like” relationships with other, sometimes drastically different organisms that give them a survival advantage. Monarchs just happen to be a wonderful example of mutualistic relationships.

Learn more:

The Monarch Joint Venture lists a number of national and regional partners; each of them will have information about monarch butterflies. The U.S. Fish and Wildlife Service, which is partnering with the National Wildlife Federation and National Fish and Wildlife Foundation, is also a source for information on milkweed and monarchs. Get free milkweed plants at monarchwatch.org.

Million Pollinator Garden Challenge

Add your garden to the Million Pollinator Gardens project this summer. Learn more at millionpollinatorgardens.org.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

Monarch butterflies have left their overwintering sites in Mexico and are heading back toward the Midwest, including the Chicago area.

Unfortunately, far fewer monarchs will be making the northward flight this year and the chance to see large numbers of these beautiful butterflies in your garden or flying across a prairie is becoming less certain.

Explore pollinators at World Environment Day, June 7.

Join us Friday, June 6, for the Make Way for Monarchs research symposium.

PHOTO: Asclepias tuberosa, a native milkweed species, in bloom.

Butterfly weed (Asclepias tuberosa) is one of many native milkweed species that provide food for monarch butterfly caterpillars and a nectar source for flower visitors such as bees and butterflies.

In the 1990s, hundreds of millions of monarchs made the journey each fall from the northern plains of the United States and Canada to forested sites north of Mexico City. In western North America, more than a million monarchs made a shorter flight to tree groves on California’s coast. However, monarch numbers have been declining for more than a decade, and this year scientists documented record low numbers. We have seen more than a 90 percent decline.

Why is this occurring? We don’t know for sure, although there are several factors that are likely contributing. Habitat loss due to urban development and large-scale agriculture are key concerns. Farms now cover vast areas and many grow genetically modified crops that allow herbicide applications to be used on and around the crop, including in areas where milkweed—the one plant that monarch caterpillars need—used to grow. These “Roundup ready” crops have been identified as a major cause of milkweed loss throughout the Midwest. Additionally, millions of acres of farms and urban land are treated with toxic insecticides. The loss of forest habitat in Mexico and the decline of monarch groves in California may also be playing a role. In the West, severe drought is likely contributing to reduced monarch populations. These threats are compounded by climate change.

We do not have to sit and watch these declines continue.

We can provide these butterflies (and other wildlife) with high-quality, insecticide-free habitats. This is not something that needs to be restricted to a distant wilderness. Indeed, it is a cause in which everyone can take part. Homeowners and farmers can plant milkweed to support monarch caterpillars, and native flowers to provide nectar for adult butterflies, and work to limit the impact of insecticides. Land managers can ensure that milkweed stands are adequately protected.

Sign up for “The Monarch Butterfly: How You Can Help Save This Iconic Species,” Saturday, June 7, at 1 p.m.

PHOTO: A native milkweed pod burst open in winter, distributing seeds.

The Milkweed Seed Finder gives you quick access to regionally appropriate seed sources, with options to search by milkweed species and by state.

The Xerces Society’s Project Milkweed has been working with native wildflower seed nurseries, the USDA Natural Resources Conservation Service (NRCS), and community partners to produce huge volumes of milkweed seed that are being used to restore monarch habitat. In just three years, this work has led to the production of 35 million milkweed seeds! As a result of this effort, milkweed seed is rapidly becoming more available in many regions of the country. To make it easier for people to find seed sources, we’ve launched the Milkweed Seed Finder, a comprehensive directory of milkweed seed vendors across the country.

In addition, the Xerces Society’s work with farmers and the NRCS has led to the creation of tens of thousands of acres of wildflower habitat that includes milkweed, across much of the monarch’s breeding range.

Aldo Leopold wrote in A Sand County Almanac, “One of the penalties of an ecological education is that one lives alone in a world of wounds.” For the sake of the monarch—and so many other species—it is time to heal as many wounds as possible.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

Did you know that one in every three bites of food you take required a pollinator visit? Pollination is essential for many of our favorite foods—from almonds to vanilla, and so many fruits and vegetables in between.

The decline of pollinators around the world is threatening not only our food supply but also the function of plant communities and ecosystems. Multiple factors play a role in pollinator decline, including land-use changes, pesticide use, climate change, and the spread of invasive species and diseases.

The well-documented plight of the iconic monarch butterfly has become emblematic of widespread pollinator decline. Perhaps many of you, like me, have childhood memories of setting out with a butterfly net and a jar with nail holes in the lid. I recall with pleasure catching and admiring monarchs up close until it was time to set them free. I worry that children may not have that simple pleasure much longer. After their previous all-time low population count in 2012–13, monarch numbers dwindled even lower this past winter (2013–14), when monitored in their overwintering location in Mexico.

PHOTO: A cluster of monarch butterflies rests on a plant, entirely covering it.

Now a much less common sight: a monarch butterfly cluster. Image by Christian Mehlführer (Own work) [CC-BY-3.0], via Wikimedia Commons

PHOTO: A monarch sips nectar from common milkweed on the Dixon Prairie.

A monarch sips nectar from common milkweed (Asclepias syriaca) on the Dixon Prairie.

In the case of the monarch, several factors are likely contributing to its rapid decline. Loss of forested wintering grounds; loss of the milkweeds, which are their larval host plants; severe weather events; and a reduction of nectar plants along their migration routes due to drought have probably all contributed. Three leading monarch experts, Dr. Lincoln Brower, Dr. Chip Taylor, and Dr. Karen Oberhauser, have all cited GMO (genetically modified) crops as a leading factor in the decline. Milkweed (Asclepias sp.) once thrived on the edges of farm fields throughout the Midwest. Modern farming techniques use herbicide-resistant crops coupled with an increased use of herbicides; the native milkweeds are disappearing, and as they go, so do the monarchs.

Make Way for Monarchs

Click here for registration and schedule information.

On Friday, June 6, the Chicago Botanic Garden will host a symposium by Make Way for Monarchs: Alliance for Milkweed and Butterfly Recovery (makewayformonarchs.org). Members of this group conduct research on monarch butterfly recovery and promote positive, science-based actions to avert collapse of the milkweed community and the further demise of the monarch migration to Mexico. They aim to promote social engagement in implementing solutions in midwestern landscapes through collaborative conservation. Speakers include Gary Nabhan, Lincoln Brower, Chip Taylor, Karen Oberhauser, Laura Jackson, Doug Taron, and Scott Hoffman Black. They will discuss monarch decline and tangible solutions we all can help implement. Mr. Black will also present a lecture on monarchs at World Environment Day, Saturday, June 7.

PHOTO: Closeup of a single, tiny butterfly egg on the underside of a leaf.

Monarch egg on a milkweed leaf by Forehand.jay (Own work) [CC-BY-SA-3.0 or GFDL], via Wikimedia Commons

There are things all of us can do: from planting milkweeds and other native plant species that provide nectar throughout the growing season, to minimizing pesticide use, and to supporting organic farmers. We can also become citizen scientists, reporting monarch observations to programs like Monarch Watch and Journey North, or working with the Monarch Joint Venture.

Perhaps, with our help, new generations of children will continue to know the joy of admiring the beautiful monarch butterfly, and then letting it go to continue its amazing migratory journey.

Learn more about pollinators at World Environment Day at the Garden on June 7, 2014.


©2014 Chicago Botanic Garden and my.chicagobotanic.org