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Monarch Habitats in the Desert

Learn what you need to know to build a Monarch habitat in your desert garden — whether it's a balcony or patio, a private home, or part of an HOA or community space. It's about more than just Milkweed.

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In this article: Western Monarch Migration | Monarchs in the Desert |
I Have Milkweed, Where are My Caterpillars? | Build a Desert Monarch Habitat | Plant Community

Learn more about Monarchs: How to Help Monarchs | Reproduction and Feeding

migration

Before we discuss how to plan and plant a monarch garden, it’s important to understand monarch migration through our local area, so you can provide the appropriate plants for when these beautiful butterflies pass through.

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A remarkable thing about monarch butterflies (Danaus plexippus) is that although it is a single species, it largely exists as two separate populations: one east of the Rocky Mountains and one to the west. There are smaller scattered populations but the majority of the monarchs on Earth occur within these two populations.

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Western Monarch Migration

In the late summer, environmental cues trigger migratory behavior. Monarchs delay reproductive development (this is called diapause) and begin to travel away from their breeding grounds towards their overwintering sites. 

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Western monarchs typically migrate towards California where they overwinter in small forested areas along the Pacific coast from just north of San Francisco south to Baja. While a shorter trip than their Eastern counterparts, it is no less remarkable. 

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These monarchs must traverse some of the most challenging landscapes of North America, including deserts, mountain ranges, some of the most intensely farmed landscapes on Earth where pesticide use is widespread, and urban landscapes virtually devoid of habitat.

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After traveling these vast distances these monarchs spend the winter clustered on the California coast in eucalyptus, pine, and cypress trees. Appropriate sites must provide the perfect microclimate that allows the monarchs to survive until the following spring.

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We are still studying and learning new information about monarch behavior. Studies have shown that some monarchs from the Southwest migrate to central Mexico, where they overwinter alongside Eastern monarchs, while others from the same area migrate to overwintering sites in California. What prompts this migration shift remains unknown.

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Like Goldilocks, monarchs require perfect temperatures: not so cold that the butterfly will freeze and not so warm that they will become active and burn too many calories, expending energy needed for the return trip. The precise climate is vital.

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Monarch Butterfly Grove Pismo Beach overwintering.jpg

Beginning in late winter to early spring environmental cues trigger breeding to resume and the same monarchs start migrating back to their breeding grounds. But unlike the fall migration which took a single butterfly, it will take multiple generations each flying a bit further, to complete this migration over spring and summer.

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Key points:

  • Monarch butterfly migration is a multi-generational feat, not a single butterfly making the round trip.

  • Diapause is a hormonally controlled state of dormancy that conserves energy to aid in winter survival.

  • The fall migration is completed by a single butterfly.

  • The spring and summer migration is completed in stages by multiple generations.

Monarchs in California and Arizona deserts

Although the majority of North American monarchs migrate, warm weather climates like southern Florida, parts of Arizona, and here in the Coachella Valley, may host monarchs year-round. These resident populations breed throughout the winter on native evergreen milkweed. 

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Coachella Valley: The monarchs in the Coachella Valley arrive late September to early October depending on the weather. These monarchs breed all winter and lay eggs on the local native evergreen Rush Milkweed, Asclepias subulata.

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On those especially cold winter days when the temperature stays below 50 degrees, the butterflies roost in the trees waiting for warmer temperatures. 

Adult monarch butterflies are most active at temperatures between 80-100 degrees. Like me, Monarchs think 84 degrees is just perfect. 

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In late spring when we begin to experience 100 degree days, the butterflies move to cooler locations. 

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Research is underway, studying our local monarchs to determine where they go in the summer. We believe they are moving to higher elevations, like the High Desert or our local mountains, but more study is necessary. This is why participating in community science projects and donating to research organizations is so important. 

I have milkweed. Where are my caterpillars?

Even when milkweed is present, the female is still selective. Females use their chemically sensitive feet to “taste” a leaf and decide if it’s a good spot to place an egg. If it is, they lay their eggs individually, generally, one per leaf.
 

They tend to avoid laying eggs on milkweed that already have caterpillars feeding on them or that are older and tougher. Instead, they look for plants with tender new growth with less competition. 


The female lays between 3 to 10 eggs at a time. The more plants available to the female the more eggs she is likely to lay and the more caterpillars that will be likely to survive.


Plant groupings of at least 3 native milkweeds. Planting several milkweeds together increases caterpillar survival rates because Monarch caterpillars in their later stages (fourth instar) move to new milkweed plants.

Researchers are studying this instinctive behavior known as plant abandonment.


Milkweed is not enough. Have you planted a variety of nectar plants to attract adult butterflies? We need both male and female butterflies for reproduction.


Is your garden hospitable to butterflies?

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How to build a successful monarch habitat in the California desert

Queen butterflies on Blue Mistflower

Choose a sunny site for your garden


Butterflies need the sun’s energy to warm up. Butterflies won’t breed when temperatures are below 60 degrees, and larvae (caterpillars) grow at temperatures between 52-94 degrees. 

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Since Monarchs arrive in the Coachella Valley in the Fall and Winter, when our temperatures often drop below 52 degrees, it’s best to put your Monarch garden in a sunny spot in your yard.

 

Include windbreaks 

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Butterflies prefer to feed in areas sheltered from the wind. A fence, shrub, or wall all work and will also provide a good setting for pupation.

 

Add native plants

 

Use only native milkweed.

 

A tree that has at least one side that is southeast or east-facing, so it has good sun in the morning. This allows the butterflies a place to roost at night and warm up in the morning sun.


A diverse array of native nectar plants, wildflowers, perennials, and shrubs that bloom during monarch season. Clumps of flowering plants will attract more pollinators than single plants scattered throughout the garden.

Certain plants, like Conocliniums and Asteraceae, support the health of monarch butterflies and their reproductive process by providing alkaloids that monarchs take up while nectaring. A male monarch can transfer these alkaloid packages to the female during mating, protecting both the female and her eggs from predators and conferring health benefits.


Monarchs can access alkaloids from the nectar of these flowers or dry plant tissue. To extract alkaloids from dry plant tissue, butterflies regurgitate saliva, which breaks down the plant cells, and then they suck up the liquid.

 

Alternatively, they can take up juice from injured plant parts.
We are just beginning to understand this behavior, and little scientific research has been done.

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Water source


Leave some bare ground for puddling. Puddling provides moisture, salt, and other minerals that male butterflies need in the reproductive process.

 

Do not use insecticides in your monarch habitat
 

Avoid pesticides - which include insecticides, herbicides, fungicides, and other poisons. Pesticides can harm and kill beneficial insects. Given enough time, ecological systems tend to find a balance in which native predatory insects manage pests.

 

In your gardens do not use insecticides in or around your pollinator habitat. If you need to use chemicals, including organic, elsewhere on your property, carefully read — and follow — label instructions.

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​As a rule, there is not a good reason to apply insecticides to a butterfly habitat.


Where NOT to plant milkweed 
We should take our cue from nature; if milkweed doesn’t occur naturally, we shouldn’t plant it.

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Western monarchs journey to coastal California to overwinter, but not to lay eggs. This is because there are some areas where milkweed does not occur naturally. 


Planted too close to the ocean, milkweed can escape hard frosts, remaining semigreen during the monarch overwintering season. With such egg laying sites available, monarchs may continue to mate and lay eggs in the winter, delaying, disrupting, or even preventing their natural cycle of fall dormancy. 


For these reasons, it is best to not plant milkweed close to overwintering sites within 5 miles of the coast between Mendocino and Santa Barbara, and in southern California, less than 2 miles from the coast. Milkweed is also naturally absent in the Coast Range of Oregon and west of the Cascade Mountains in Washington.


In these areas, the best way to help the occasional monarch that passes through is to plant native flowers that provide nectar. Fall, winter, and spring blooming native plants will provide nectar for nearby overwintering monarch populations.

habitat

Monarch Plant Community for the Low Desert in California

A community is a group of plants that naturally grow together to form a habitat. In this community, you will find native milkweed, the caterpillar host plant, trees for the butterflies to roost in, shrubs for both nectar sources and windbreaks, and annual and perennial nectar resources along with other plants that naturally support the ecosystems's overall health and sustainability.

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What not to plant

Lantana is a popular shrub and ground cover in the Coachella Valley and Southwest for both humans and butterflies. 

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When we choose which varieties to plant we need to be conscientious of which ones can become invasive. West Indian Lantana, Lantana camara, is considered one of the most invasive plants in the US and is on the California Invasive Plant List.

Learn more about Monarchs: How to Help Monarchs | Reproduction and Feeding

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