Milkweed Plantings Needed to Restore Threatened Monarch Butterfly

November 15, 2018

Written By Adam Buckallew

Every autumn, millions of vibrantly colored monarch butterflies embark on an incredible mass migration. The remarkable trip takes the butterflies up to 3,000 miles, traveling as far south as central Mexico before that generation’s offspring return to the upper Midwest and Canada in the spring. The wonder of this natural phenomena could soon disappear if action isn’t taken to plant more milkweed, the only plant capable of sustaining the species. Milkweed provides essential habitat and is the sole source of food for monarch caterpillars.

Since the 1990s, the eastern migratory population of monarch butterflies has dropped by more than 90 percent. In that same timeframe, an estimated billion-plus stems of milkweed have been lost due to herbicide spraying and land development. In addition to breeding habitat loss, other factors such as adverse weather conditions, loss of overwintering habitat, disease and exposure to contaminants have contributed to the decline of the monarch.

The widespread milkweed losses have imperiled Monarchs to the point the U.S. Fish and Wildlife Service is weighing whether to include the butterfly on the endangered species list. The service is expected to decide whether such a listing is warranted by June 2019.

In a 2017 study conducted by the U.S. Geological Survey (USGS), the University of Arizona and partners, scientists developed potential scenarios for incorporating milkweed into the midwestern U.S. landscape. The researchers found converting marginal cropland to monarch-friendly habitat provides the best opportunity for adding milkweed to help restore the eastern migratory monarch population. However, in addition to agricultural lands, the authors emphasized that planting milkweeds into other kinds of lands, including protected areas and urban and suburban locations, may be necessary.

“The main finding of our study is that an all-hands-on-deck approach could be essential to restoring the massive amounts of milkweeds needed to make the monarch population healthy again,” said Wayne Thogmartin, a USGS scientist and the lead author of the report. “These findings offer great hope for citizens from all sectors working together to reverse the substantial decline of these iconic butterflies.”

A USGS-led report found more than 1.6 billion additional milkweed stems may be needed in North America to return eastern migratory monarchs to a sustainable population size.

Much of the milkweed that once grew along the monarchs’ migration route has been wiped out from agricultural lands, as it’s long been viewed by farmers and ranchers as a nuisance. However, those views are beginning to change.

A broad-based coalition of agricultural organizations launched Farmers for Monarchs in March 2018. This united effort by farmers, ranchers, landowners, the agriculture industry, conservation groups and others seeks to encourage establishment and expansion of pollinator and conservation habitat—including planting milkweed along the monarch butterfly seasonal migration route.

The idea behind the effort is to do enough to save the Monarch voluntarily before potentially burdensome regulations from an endangered species listing come into play. Regulatory action could include limiting pesticide and herbicide use on farmland.

Farmers and ranchers are uniquely positioned to restore monarch habitat. Roughly two out of every three acres in the continental United States is privately owned, and much of that land is used for agrarian production.

“Agriculture can play a crucial role in maintaining a beneficial relationship between native pollinators, native plants and food production,” says Tom Melius, Midwest regional director for the U.S. Fish and Wildlife Service. “You can help monarchs by planting native milkweed and nectar plants in your backyard, on your back forty and on every back road in between.”

Conservation practices that benefit monarch butterflies and other insects also help reduce erosion, increase soil health, control invasive species, provide quality forage for livestock and make agricultural operations more resilient and productive.

Through the Farm Bill, the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) provides assistance to agricultural producers interested in making conservation improvements that benefit the monarch and other struggling pollinator species such as bees, birds and beetles, while also increasing the productivity and resiliency on working lands. Other programs conducted by local and state agencies and non-profit groups are also available.

Farmers, ranchers and forest landowners are voluntarily combating the decline of monarchs by adding and maintaining high-quality monarch habitat on their land with a diverse mixture of native wildflowers, milkweed and other beneficial plants. NRCS conservationists and wildlife biologists can help farmers identify which practices best fit their lands. Fencerows, pivot corners, conservation lands, ditches, buffers and other low-productivity lands typically serve as excellent areas to establish pollinator habitat.

NRCS offers more than three dozen conservation practices that can benefit monarchs by managing for healthy stands of milkweed and high-value nectar plants and protecting these stands from exposure to pesticides. While many of these practices may target improving grazing lands or boosting soil health, simple tweaks to the practice can yield big benefits for monarchs.

Fall is the perfect time to plant milkweed. Consider adding some to any patch of land you have available. Every planting will bring the majestic monarch one step closer to recovery.

How farmers and private landowners can help monarchs:

• Establish a diverse habitat that has a mixture of native wildflowers, milkweed and other beneficial plants.
• Plant pollinator habitats in sites such as field borders, pivot corners, conservation lands, ditches, buffers and other low-productivity land.
• Work with local partners also interested in conserving pollinators. There are several financial and technical assistance programs available.
• Contact your local USDA service center for more information about technical and financial assistance available from NRCS.