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Desert Milkweed

Asclepias erosa

1 gallon

Desert Milkweed

Out of stock

3'x2'

Sizes:

Desert Milkweed – Asclepias erosa
Also known as: Desert Silkweed

It’s a common misconception that Asclepias subulata—Rush Milkweed—is the only “desert milkweed” in the low desert. In fact, Asclepias erosa is the species technically known as Desert Milkweed. Both species are native to southern California, Arizona, and northern Baja California, where they are most abundant in desert regions.

In the low Colorado Desert, A. erosa typically dies back in winter and re-emerges in spring, blooming from late spring into early summer. Its growth cycle may vary in the higher Mojave Desert. In low desert gardens, it is best used alongside Asclepias subulata to extend bloom periods and provide a wider range of resources for pollinators. When planted alone, A. erosa may be dormant for a large portion of the monarch season.

This upright perennial features clusters of white to pale yellow flowers that contrast with green to yellowish stems. It thrives in sandy or rocky well-drained soils, and prefers full sun and dry desert conditions. The flowers are hermaphroditic and are pollinated by a variety of native insects. The thick, milky sap contains toxic cardiac glycosides that deter herbivores. Historically, local Indigenous tribes roasted the sap to a solid form and chewed it like gum.

Wildlife Value
Host Plant: Monarch (Danaus plexippus); Queen (Danaus gilippus)
Nectar Source: Monarch (Danaus plexippus); Queen (Danaus gilippus); Tarantula Hawk Wasp (Pepsis spp.); Ceraunus Blue (Hemiargus ceraunus); various Swallowtails (Papilio spp.)
Bird Resources: Nectar; Insects; Caterpillars; Seeds
Bird Species: Anna’s Hummingbird (Calypte anna); Costa’s Hummingbird (Calypte costae)
Bees: Native bees; European Honey Bee (Apis mellifera)
Other Wildlife: Beetles

Plant Care

Native region:

Local Native; Mojave Desert

Water needs:

Low

Exposure:

Full Sun; Filtered Shade

Mature size:

3'x2'

Growth rate:

Moderate

Flower color:

Creamy Yellow

Flower season:

Spring; Summer; Fall

Pruning:

None

Cold Hardiness:

5 Degrees

Nectar-producing:

Yes

Attracts pollinators:

Yes

Nighttime pollinators:

Butterflies or Moths:

Yes

Monarchs:

Yes

Larval host:

Yes

Bees:

Yes

Bats:

Birds:

Yes

Nest site:

Nest materials:

Yes

Rabbit-resistant:

Yes

Tortoises:

Growing Plants in the Desert — Important Information

The information presented here is, to the best of my knowledge, accurate and based on reliable research, personal experience in my own garden, observations from other gardens I’ve visited, and time spent studying plants in their native habitats. I always welcome your feedback and experiences to help me continue educating others!

Cacti:
In my experience, cacti are much happier in filtered shade here in the low desert of the Coachella Valley. Their colors are more vibrant and they tend to bloom more profusely, especially the non-native varieties. If you look closely at how our native barrel cactus and beavertail prickly pear grow in the wild, you’ll often find them tucked among rocks or beneath the shelter of creosote and other shrubs.

⚠️ A note of caution: Cacti and succulents are often illegally collected from the wild, which not only damages plant populations but also disturbs entire ecosystems. In some cases, wild populations of cacti have even gone extinct because of this practice. When purchasing these plants, always be sure they’ve been legally obtained. Look for nursery-grown stock or plants with a native plant certification, and keep that documentation for your records.

Light Requirements:
In our desert (Sonoran/Colorado), “full sun” doesn’t always mean what you might think. Many so-called full-sun plants benefit from and actually appreciate some late-afternoon filtered light—especially during the intense summer months.