It Takes a Landscape

by | Sep 20, 2016 | Conservation

Monarch butterfly on shrubby boneset, , Nymphalidae danaus plexippus, by Val Bugh

Monarch butterfly on shrubby boneset. PHOTO Val Bugh

ACROSS NORTH AMERICA, people are rallying to save a relatively small but charismatic orange and black butterfly — and for good reason. The loss of the monarch butterfly, an insect that migrates an astonishing thousands of miles over multiple generations between Mexico and the northern U.S. and Canada, would be devastating.

The butterfly’s recent demise from a population of 1 billion to 33 million has been well-documented by researchers and well-covered by the major media. Much of the attention north of the Rio Grande has focused on declining numbers of North American native milkweeds — the monarch’s sole host plants — caused by agricultural practices and increased land development. Rightly so.

FALL POWER PLANTS

Ageratina havanensis

Shrubby boneset
Ageratina havanensis

Gregg's mistflower

Gregg’s mistflower
Conoclinium greggii

Maximilian sunflower

Maximilian sunflower
Helianthus maximiliani

Frostweed

Frostweed
Verbesina virginica

Fall aster

Fall aster
Symphyotrichum
oblongifolium

 

Monarchs cannot reproduce without milkweeds, and planting more of them across the U.S. is a critically important action. Federal agencies, universities, conservation organizations, citizen groups and botanic gardens, including the Lady Bird Johnson Wildflower Center, have rallied behind the milkweed banner. This is a great testament to the care and passion that we have for our environment.

But it takes more than milkweeds to help monarchs. It takes landscapes.

 

Monarchs Need Fuel

In a 2016 study, researchers from Cornell University analyzed 22 years of data to find that, despite the milkweed decline, monarch populations are actually doing pretty well in their summer breeding grounds in the north-central U.S. and Canada. There are just about as many adults flying around that area these days as there were years ago. That’s great news, and it shouldn’t stop gardeners and everyone else from planting more milkweeds. We still need more milkweeds.

Yet, somewhere between Ohio and Michoacán, the monarchs are losing numbers during the fall migration. The Cornell researchers point to both lack of nectar plants and habitat fragmentation along the migration path through the U.S., which funnels right through Texas.

Adult monarchs flying south through Texas need fuel — and lots of it — from fall-blooming nectar plants. For millennia, the butterflies have pit-stopped on native fall bloomers in our state, but we are losing these nectar plants for the same reasons we lose milkweeds: expanding agriculture and development. Additionally, habitat fragmentation could be making the pit stops too far apart for these small — though tough — butterflies to reasonably fly between. (Imagine running from Ann Arbor to Austin with no snacks or breaks along the way. It simply wouldn’t be possible.)

 

Plant More Nectar Plants

What we can do to remedy this is simple: we need to create more landscapes that are connected to each other (or at least not too far apart) and filled with diverse assemblages of native plants, including nectar plants for food and trees and grasses for roosting, resting and sunning. We can do this in our cities, in our rural areas, in our backyards and front yards, in our suburbs, on rooftops, in planter beds, on highways and in public parks.

The good news is, those same landscapes will support other pollinators, migrating hummingbirds and songbirds, frogs and foxes. And if they are done right, they’ll help retain and filter water and provide us with the miraculous experience of watching colorful butterflies flit through the air.

As many people have discovered, finding and planting native milkweeds in Texas can be tricky (but we’re working on that). Planting a few high-impact nectar plants is potentially much easier. We recommend that Texans throughout the monarch flyway plant more of these five fall-blooming superstars to support migrating monarchs: Gregg’s mistflower, shrubby boneset, frostweed, Maximillian sunflower and fall aster (see sidebar). If you can’t find them at your nursery or seed source, demand them! Consumer demand drives supply.

Fall is the best time to plant next year’s nectar plants, and they may be just as important as milkweeds for the health of monarchs. Let’s think big (like Texans do) to create robust, native-first landscapes across the state. These landscapes could give the monarchs — and all of us — just the boost needed.

 

What You Can Do