Got Milkweed?

Got Milkweed?


Each fall, hundreds of millions of monarch butterflies migrate from the United States and Canada to mountains in central Mexico where they wait out the winter until conditions favor a return flight in the spring. The monarch migration is truly one of the world’s greatest natural wonders yet it is threatened by habitat loss.


The Issue

In 2022, the International Union for Conservation of Nature declared the eastern migratory monarch butterfly endangered. Threats for monarchs include habitat loss due to urbanization, agricultural intensification, widespread pesticide use, and climate change causing increased incidences of severe weather like droughts or freezing rain events.

Why it Matters

Butterflies are “accidental pollinators.” They aren’t specifically looking for pollen but visit flowers looking for nectar and then transfer pollen and fertilize plants in the process. Pollinators are vital to supporting our food system. Without pollination, plants cannot produce fruit or seeds.

The Solution

You can play an important role in helping to keep monarchs alive and well by planting milkweed seeds and creating your own monarch waystation.  Although monarch butterflies feed on many different kinds of plants, milkweed is essential for the species.

With its own Butterfly Garden and the initiation of the Milkweed Project, Tohono Chul is working to increase monarch habitat by encouraging our friends to help install waystations across the Sonoran Desert. We invite you to join us in this effort!



No seeds? No problem.

Contact us for your seed packet!

What’s in the seed packet?

•  Butterfly Milkweed (Asclepias tuberosa)
•  Antelope Horn (Asclepias asperula)
•  Showy Milkweed (Asclepias speciosa)
•  Arizona Milkweed (Asclepias angustifolia)
•  Pine Needle Milkweed (Asclepias linaria)
•  Desert Milkweed (Asclepias subulata)

Ready to Plant?

Milkweed seeds, like the ones in your packet, can be planted directly in the soil or started indoors. When planting directly in soil, sow seeds by scattering them on the soil surface and covering them with about 1/4 inch of soil. Water the area frequently after planting until plants become established.

*STORE SEEDS IN REFRIGERATOR UNTIL READY TO PLANT

To start indoors, place your seeds between paper towels and soak them in warm water for 24 hours prior to planting. Fill plastic flats with a potting soil mix, thoroughly soak, and let drain. Sow seeds by scattering 1/4 to 1/2 inches apart and covering them with an additional 1/4 inch mix. Gently mist the soil surface. Allow to grow for 4-8 weeks before transplanting.



What is a Monarch Waystation?

Monarch Waystations are areas that provide resources (milkweeds and nectar flowers) for monarchs to produce successive generations and sustain their migration. Without these resources in the breeding areas in North America, monarchs would not be able to produce the successive generations that culminate in the migration each fall. It is important to keep monarchs’ basic needs in mind when creating a waystation or butterfly garden.

  • Host plants: Also called larval plants—are annuals or perennials where butterflies lay their eggs. As the tiny caterpillars hatch from the eggs they will consume the leaves and often the flowers as food. While hungry caterpillars can quickly defoliate a plant, new leaves quickly grow afterward. You can enjoy watching the entire lifespan of butterflies in your yard by including host plants. Plus, more butterflies will often linger in your yard looking for a mate or to find just the right place to lay their eggs.

  • Shelter: Butterflies need trees or large shrubs for protection from the wind and heat of the day as well as a place to spend the night. When the weather is favorable, look for them on the southeast side of trees and tall bushes warming in the rising sun.
  • Nectar plants: All butterflies need nectar to sustain their adult life but not all flowers are created equal. Butterflies have favorites and they can vary by season. Butterflies will visit nectar plants in the spring but late summer and fall are the premier seasons. To attract a wide variety of visitors, make sure there are flowering plants in your garden throughout the entire butterfly season. Clusters of several plants are most effective and visible to flying butterflies.

  • Moisture: In dry conditions (low humidity and low rainfall), monarchs may benefit from supplemental moisture. This can be as simple as irrigating deeply when they are present. You may see monarchs sipping from morning dew or moisture on leaves or puddling on damp ground.

Grab these host and nectar plants for your monarch waystation at the Tohono Chul Retail Greenhouse:

  • Blue Mist (Conoclinium greggii)
  • Dogweed (Thymophylla pentachaeta)
  • Lemmon Marigold (Tagetes lemmonii)
  • Tahoka Daisy (Machaeranthera tanacetifolia)
  • Lantana spp.
  • Chuparosa (Justicia californica)
  • Globemallow (Sphaeralcea species)
  • Wild Desert Petunia (Ruellia nudiflora)
  • Salvia spp.
  • Thistle (Centaurea and Cirsium)
  • Verbena/Vervain (Glandularia gooddingii, Glandularia bipinnatifida)
  • Desert Zinnia (Zinnia acerosa, Zinnia grandiflora)

You can diversify with native grasses, shrubs, and trees, as well. Many native butterflies depend on these host plants! Click here for Regional Planting Guides.



When to Plant

Maximize Your Results

For those with a garden or existing landscaping, water the ground, then sow the seeds in October/November or February/March.

If you are starting new, perform the preparation steps four to eight weeks earlier. Germination happens in about seven to 10 days for a fall planting and can take up to 50 days for a spring planting.

Be sure to check online for premier planting times. In the lower deserts, this can be in early March or, in the higher elevations, in May. The fall is also a beneficial time to plant since soil temperatures are still warm. Knowing your local planting times as well as appropriate varieties of milkweeds, nectar plants, bushes, and trees is key to a successful habitat.

Another consideration is irrigation. Even native plants will need supplemental moisture until they are well-established, usually at least two years. Many butterfly gardens benefit from drip irrigation or occasional deep watering during dry spells. Be sure to plan for your watering needs before you plant.

Get your plot ready by following one or more of these sustainable management practices:

  1. Water the plot as needed to maintain growth
  2. Amend the soil (add nutrients or other materials) to achieve proper conditions before planting
  3. Eliminate the use of insecticides
  4. Mulch around the base of plants to reduce the growth of weeds and retain water
  5. Manage the density of the plot by thinning (removing plants to minimize crowding)
  6. Remove dead stalks, etc. before the next growing season
  7. Remove invasive species from the site
  8. Use natural compost for fertilization
  9. Add other features (e.g.- fruit feeders, bee nesting boxes, other host plants, etc.)

Can I plant other seeds with milkweed?

Yes! We encourage you to also grow host and nectar plants to provide nutrients and breeding spaces for adult monarchs migrating through Tucson.

Share Your Success!

Once your milkweed is fully established, take a picture and post it on social media using the hashtag #TCmilkweedproject.


Helpful Resources

Monarch Habitat Installation Services

To qualify as a monarch waystation, plant at least ten milkweeds (Asclepias spp.) and include other host plants to draw a variety of other butterflies to your garden. Watershed Management Group’s Green Living Co-op can help you select appropriate pollinator plants, install your monarch habitat, and register as a monarch waystation.

Monarch Waystation Certification

Once established, you can certify your yard as a monarch habitat and contribute to monarch conservation efforts! Existing habitats that meet the criteria for a monarch waystation (or that can be easily modified to meet them) may also be registered/certified as official monarch waystations. Upon certification your site will be included in the International Monarch Waystation Registry, an online listing of Monarch waystations, and you will be awarded a certificate bearing your name and your site’s unique monarch waystation ID number.


Displays a map of monarch waystations in the US.

Together we can ensure future generations and create a better world for our pollinators.
Get Planting today! #TCmilkweedproject