Western Monarch Butterfly Project

Western Monarch butterflies are in precipitous decline because of habitat loss, pesticides, and climate change. The Del Mar Foundation has partnered with the Del Mar Garden Club and other volunteers in our community to encourage Del Mar residents to participate in conservation efforts to ensure that these beautiful pollinators survive and thrive.

As part of this community project, a demonstration garden will be planted at the Civic Center (north end of the Civic Center plaza). The garden will feature Narrow Leaf Milkweed (Asclepias fascicularis), the locally-native milkweed that serves as a host plant for monarchs, as well as nectar plants that attract and support monarchs.

In the Resources section below, you’ll find a plant list of locally native plants that are appropriate for a monarch habitat garden, along with additional plant lists and resources. You’ll also find additional information on Western Monarchs, including: the Monarch life cycle, conservation actions, and why it is important to use locally-native milkweed in favor of tropical milkweeds, which can harm western monarchs.

Why the focus on Western Monarchs? Del Mar’s Mayor signed the Mayors’ Monarch Pledge on April 29, 2022, joining other mayors across the country to take action to help save monarchs, whose population has declined precipitously. Here is the story, by the numbers, for Western Monarchs:

Resources for Information

Western Monarch Call to Action
Xerces Society for Invertebrate Conservation.
https://xerces.org/western-monarch-call-to-action

This Western Monarch Call to Action identifies a set of rapid-response conservation actions that can help the western monarch population bounce back from its critically low overwintering size, and set the stage for longer-term efforts to reverse population decline due to stressors such as habitat loss and degradation, pesticides, and climate change.
Note: Xerces Society generally recommends not planting milkweed within 1 mile of the coast south of Santa Barbara. We consulted with Xerces’ agronomist to confirm the suitability of Narrow Leaf Milkweed in Del Mar gardens.

Potential Risks of Growing Tropical Milkweed for Monarchs
Learn why year-round tropical milkweed fosters greater transmission of the protozoan Ophryocystis elektroscirrha (OE), increasing the likelihood that monarchs become infected with the debilitating parasite. Recommended actions: cut back tropical milkweed in the winter and fall months, and instead of planting tropical milkweed, plant native milkweed.
https://www.monarchjointventure.org/images/uploads/documents/OE_fact_sheet_Updated.pdf

Western Monarch Biology: The Monarch Life Cycle
Learn about the Western Monarch’s llife cycle, migration and wintering behavior.
https://www.monarchmilkweedmapper.org/western-monarch-biology/

Plant Lists

Native Plants for Del Mar (PDF)
This plant list focuses on locally-native plants that support butterflies and birds,with links to additional information and photos of each listed plant.

Nectar Plants: Califonia (Xerces Society)
https://xerces.org/sites/default/files/publications/19-046_01_MonarchNectarPlants_California_web-4pg.pdf
Note: Xerces Society generally recommends not planting milkweed within 1 mile of the coast south of Santa Barbara. We consulted with Xerces’ agronomist to confirm the suitability of Narrow Leaf Milkweed in Del Mar gardens.


Butterfly Farms (Encinitas) Plant List (PDF)