More than silk plants: Creating a migratory oasis for monarch butterflies

While monarch butterflies depend on milkweed as host plants for eggs and caterpillars, they require a variety of nectar-producing plants for their fall migration.

Laura McKenzie/Texas A&M AgriLife Marketing and Communications

Experts at Texas A&M AgriLife said that with the summer season upon us, now is the ideal time to create an oasis for monarch butterflies as they pass through Texas on their annual fall migration to Mexico.

Although monarch butterflies are generally known for their special relationship with milkweed, they rely on a wide variety of nectar-producing plants during fall migration, says Wizzie Brown, Texas A&M AgriLife Extension Service program specialist in the Department of Entomology at the Texas A&M College of Agriculture and Life Sciences.

“They typically migrate south through Texas from September to November,” Brown said. “At that time, our goal is to give them enough nectar and energy to reach their wintering grounds.”

Monarch butterflies and milkweed in autumn

There are about 30 native milkweed species in Texas. Although these plants provide nectar, their primary function in the spring is to serve as a host plant for the eggs and development of monarch butterfly caterpillars.

However, tropical milkweed, a popular non-native variety often sold in garden centers, blooms longer into the fall than native milkweed species.

For this reason, Dr. Mike Arnold, professor and director of gardens at Texas A&M University, recommends pruning the tropical milkweed toward the beginning of fall.

“If you don't cut it back, some butterflies might be tempted to stay because they now have a safe food source there,” Arnold said.

The remaining monarch butterflies face the dangers of harsh winter temperatures and scarce resources. They are also vulnerable to parasites that prefer late fall and winter.

“We plant native and tropical milkweeds in our garden so that we can provide a variety of host plants for the monarch butterfly in the spring. However, as fall approaches, we cut our tropical milkweeds back to the ground,” Arnold said.

A smorgasbord of autumn nectar options

With a migration journey of around 3,000 miles, it is crucial for monarch butterflies to find food along the way. Brown and Arnold said there are a variety of native, nectar-producing perennials that provide beautiful landscaping options, thrive in the often harsh Texas climate and, most importantly, benefit monarch butterflies and other pollinator species. Those choices include:

  • Gregg's Mistflower.
  • Frostweed.
  • Autumn Aster.
  • Maximilian Sunflower.
  • Blazing Star varieties.
  • Goldenrod varieties.
  • Flame acanthus.
  • Buttonbush.

Arnold says now is the time to plant these fall-blooming perennials so they can become relatively well established before the stressful summer heat.

Annual flower species provide additional nectar sources and add color to a pollinator landscape. Although not native to Texas, annuals such as zinnias, marigolds and cosmos thrive in the region and add dynamic color to the landscape.

A monarch butterfly lands on an orange flower, with more orange flowers below.

A variety of native nectar plants can provide food for butterflies while adding color to a garden or other outdoor space.

Laura McKenzie/Texas A&M AgriLife Marketing and Communications

If landowners want to plant these flowers specifically for monarch butterflies, Arnold recommends waiting until mid- to late summer to plant.

“If you plant them now, those blooms will be at their peak during the heat of summer before migration,” Arnold said. “With a little planning, you can ensure the flowers are in full bloom during monarch migration.”

In addition to nectar sources, it's always a good idea to provide insects with safe access to water, Brown said.

“I recommend a shallow bowl with pebbles or decorative shells that provide a landing area above the water,” Brown said. “To avoid mosquitoes, you need something that dries out every three to five days, but that also means you'll need to refill it with clean water.”

Incorporating pollinators into land management objectives

Chase Brooke, AgriLife Extension small-area and wildlife management program specialist in the Division of Rangeland, Wildlife and Fisheries Management, said paying attention to plant diversity is a good strategy whether managing a suburban garden or an expansive pasture.

“Anything we do to bring native plant diversity into our landscape and encourage pollinators is always good,” he said.

Brooke said concerted conservation efforts at the neighborhood level, such as incorporating pollinator gardens and native vegetation into residential and community properties, are important as the Texas landscape becomes increasingly urbanized and fragmented.

Small Acreage – Big Opportunity is a joint project between AgriLife Extension and the Texas Wildlife Association designed to provide owners of small parcels (40 acres or less) the opportunity to explore wildlife management options and achieve their conservation goals.

“A person with a small plot of land may not feel like they can have a positive impact on wildlife, but a neighborly approach can make an incredible difference for pollinators, migratory birds and small mammals,” Brooke said. “There are many more ways to help wildlife than some initially think.”

Adding native plants can save landowners money

These measures not only benefit wildlife, but can also benefit the landowner's wallet.

Landowners who manage their agricultural lands for pollinators or other wildlife and meet certain criteria are eligible to convert their agricultural use value into reduced property tax rates under the state's wildlife tax assessment.

“Generally speaking, what's good for monarchs is good for other pollinators,” Brooke said. “Our focus is to incorporate things that are good for pollinators and other wildlife, while also helping landowners meet their management goals.”

Anna Harden

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