Antelope Horns Milkweed (Asclepias asperula), Texas Hill Country roadside. Photo: Monika Maeckle/Texas Butterfly Ranch

Anyone who has driven the long roads of the United States highway system has seen the variation possible along the roadside – trees, flowers, invasive plants. Everything from managed forests to clipped lawns line the massive acreage of the transportation system that is lost to farming or other development.

With the expansion of land that is intensively farmed rather than set aside for conservation, and the triumphal march of broad-spectrum herbicides, the room for native plants such as milkweed has dramatically decreased. With that shrinking, the insects which rely on those plants and flowers are suffering as well.

Case in point: the monarch butterfly. Even without the loss of its main source of nutrition during annual migration, the monarch population is in steep decline. Logging in Mexico has cut into the monarch’s breeding grounds, temperature fluctuation has affected its migration. Populations are down by 59% this year compared to the previous winter.

Trees with monarchs in Mexico
Photo by Jim Lovett/Monarch Watch

Monarch Watch, a non-profit organization that works to protect the monarch butterfly in North America, has a suggestion: Use roadside acreage along the migratory path of the butterfly to plant native plants and milkweed. Rather than plant or maintain large strips of grass, common in many states, highway roadsides and median strips could be used to conserve the plants that have disappeared due to agriculture and residential development.

This would also go some way toward protecting some of the creatures that rely on these plants. Monarch Watch also suggests planting milkweed plugs, i.e. plants that will blossom this 2013 season for the current migration, in any available patch or acreage that lies along the migratory path. According to the group, one major event or disaster – a bad season of temperature change, a particularly bad storm – could send the monarch population into a death spiral.

Roadside vegetation management has been under discussion for quite some time as a potential for conservation efforts.

Even in a time fiscal belt-tightening, the milkweed proposal seems like a good investment in highway beautification and wildlife conservation, even if there is a certain irony in creating a haven against habitat diminishment and climate change on the very byways of one of the main culprits, the road of the fossil-fuel based culture, by planting what are generally considered to be native weeds wiped out by another major culprit, successful and efficient agriculture.

Monarch and milkweed
Image: The Barnegat Bay Partnership

More:

TakePart article – One Beautiful Thing You Can Do to Help Monarch Butterflies

Monarch Watch website, which also supplies milkweed seed and plugs, and a list of other suppliers.