The Decline of Monarch Butterflies

The western population of monarch butterflies has decreased by more than 99% since the 1980s. In 2017, Salem joined cities across the United States, Canada, and Mexico to help save this important species. In May 2025, Mayor Julie Hoy renewed the City’s commitment to restoring monarch habitats by continuing to participate in the National Wildlife Federation’s Mayor’s Monarch Pledge. We are working to increase habitats for monarchs and other pollinators throughout the city and encouraging residents to join us. Together, we can protect this beautiful and vital species.

Why This Matters

Monarch butterflies are some of the most recognized and loved insects in North America. However, their population is rapidly declining. Monarchs play a crucial role in pollination, which supports ecosystems and food production. Without them, our environment could face serious problems. Salem’s residents have a unique opportunity to help reverse this trend. Since nearly half of Salem’s urban landscape consists of residential properties, community members can make a big difference by creating spaces that are friendly to monarchs.

The Problem

Monarch butterflies face many threats, including habitat loss, pesticide use, and climate change. Herbicides and pesticides used to control weeds and pests often kill milkweed, the only plant where monarchs lay their eggs and the main food source for their caterpillars. Without milkweed, monarchs cannot complete their life cycle. Land clearing and urban development also reduce the availability of milkweed and nectar-producing plants. Climate change may further disrupt their migration patterns and breeding cycles.

How You Can Help

Plant Native Milkweed

Monarch caterpillars depend entirely on milkweed to survive. Planting native milkweed in your garden, yard, or neighborhood is one of the best ways to support monarch populations. In our region, the following species of milkweed are ideal:

• Narrow-leaved Milkweed (Asclepias fascicularis)
• Showy Milkweed (Asclepias speciosa)

Important: Avoid planting tropical milkweed, as it is not native to the United States and can disrupt monarch migration.

Create a Pollinator Garden

In addition to milkweed, plant a variety of native nectar-producing flowers to provide food for monarchs and other pollinators. The Xerces Society offers a list of pollinator-friendly plants for the Maritime Northwest Region.

Here are some tips for creating a pollinator-friendly garden:

• Use the Xerces Society's list of pollinator plants suitable for the Maritime Northwest Region.
• Garden organically and limit the use of pesticides and herbicides.
• Educate others about pollinators and how they can help.
• Look for butterfly flowers that bloom from May to September.
• Choose plants with overlapping bloom times.
  • Download: Clean Streams Blooming Timetable Brochure (pdf)
• Plant a single species in clusters in sunny locations.
• Ask your nursery if their plants are free of systemic insecticides, which can harm butterflies and other beneficial insects.

What the City of Salem is Doing

The City of Salem is taking steps to support monarch conservation:

• Encouraging Residents: We encourage community members to plant monarch-friendly gardens at their homes or in their neighborhoods.
• Partnering with Community Groups: We work with local garden groups to promote planting native milkweed and nectar plants.
• Revising Mowing Practices: The City is adjusting mowing schedules on public property to allow monarch and pollinator habitats to thrive.
• Creating Demonstration Gardens: Monarch-friendly gardens have been planted at City Hall (555 Liberty Street SE) and Eola Ridge Park (Dan Avenue NW).
• Engaging Schools: We collaborate with schools to plant milkweed and nectar plants in school gardens. Schools can contact us to schedule presentations or join our mailing list.
• Adopting Safer Practices: The City is working to reduce the use of harmful pesticides.

Facts about the Monarch

• Scientific name: Danaus plexippus
• A group of butterflies is called a "kaleidoscope" or "flutter."
• Wingspan: 3.7–4.1 inches
• Weight: 0.0095–0.026 ounces (less than the weight of a dollar bill)
• Average lifespan: 6–8 months
• Migration: Monarchs west of the Rocky Mountains overwinter on the California coast, while some travel as far as Michoacán, Mexico—a journey of about 2,500 miles.
• Flight distance: Monarchs can fly 50–100 miles per day. The longest recorded flight in a single day is 265 miles.