Desert Milkweed
Asclepias subulata
A vital native butterfly host plant with rush-like stems that supports monarch and queen butterfly populations.
Cold hardy to around 20°F, USDA 9-11; a low- and mid-desert Sonoran native.
AMWUA Notes
Native and extremely drought tolerant butterfly host needing no irrigation once established.
Care Guide
Needs no supplemental water once established; give an occasional summer soak only in extreme drought.
Cut back leggy or frost-damaged stems in late winter to refresh; wear gloves, as the milky sap is irritating.
Not necessary in native soil.
Hosts monarch and queen caterpillars plus oleander aphids—leave them for the butterflies rather than spraying.
Evergreen and heat-loving; frost hardy in the low desert and a key year-round monarch host.
Soil, Feeding & Propagation
Native or decomposed-granite desert soil; sharp-draining and lean
Needs sharp, fast-draining soil.
None — thrives in lean desert soil without fertilizer.
Seed
4-5 ft
Deep but non-invasive taproot typical of milkweeds; site permanently, as it resents transplanting
Placement Tips
- •Site in a pollinator or wildlife garden with room for a 5 ft spread.
- •The leafless, rush-like stems tolerate reflected heat near walls.
- •Plant in fast-draining soil.
- •Keep the sap away from skin and eyes.
Features
Best Uses
Ecological Value
Attracts
Wildlife Value
Companion Plants
Quick Stats
Design Styles
Include in Your Project
Love Desert Milkweed? Our landscape team sources from wholesale nurseries and can incorporate it into your design.
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Use this care guide to maintain your Desert Milkweed. Questions about your landscape? Reach out anytime.
Data from 2024 AMWUA “Landscape Plants for the Arizona Desert” guide.
Desert Milkweed — common questions
Answers for low-desert Phoenix conditions, drawn from this plant’s growing data.
How much water does Desert Milkweed need in Phoenix?
Desert Milkweed is a very low-water accent plant once established. Needs no supplemental water once established; give an occasional summer soak only in extreme drought. Native and extremely drought tolerant butterfly host needing no irrigation once established.
How big does Desert Milkweed get?
Expect roughly 2 ft tall and 5 ft wide at maturity, with a slow growth rate. Allow about 4-5 ft of spacing when planting. Deep but non-invasive taproot typical of milkweeds; site permanently, as it resents transplanting.
Can you plant Desert Milkweed near a pool?
Yes. Desert Milkweed is considered pool-friendly, meaning it stays clean enough around water features and hardscape. Litter is rated low.
Can Desert Milkweed handle Arizona heat and winter frost?
Desert Milkweed is hardy in USDA 9-11 and wants full sun. Cold hardy to around 20°F, USDA 9-11; a low- and mid-desert Sonoran native. Evergreen and heat-loving; frost hardy in the low desert and a key year-round monarch host.
Does Desert Milkweed have thorns?
No. Desert Milkweed is thornless, so it is safe alongside walkways, patios and play areas.
Is Desert Milkweed safe around pets?
Desert Milkweed is listed as pet-friendly in this guide. If your dog is a determined chewer, check any new plant with your vet before planting.
When does Desert Milkweed bloom in Arizona?
Desert Milkweed blooms in spring, with yellow flowers. The bloom draws hummingbirds, butterflies.
How much maintenance does Desert Milkweed need?
Desert Milkweed is low-maintenance. Leaf, flower and pod litter is rated low. Cut back leggy or frost-damaged stems in late winter to refresh; wear gloves, as the milky sap is irritating.
What kind of soil does Desert Milkweed need?
Native or decomposed-granite desert soil; sharp-draining and lean. It needs no supplemental feeding. Not necessary in native soil.
Is Desert Milkweed native to Arizona?
Yes. Desert Milkweed is native to Arizona and to the Mohave and Sonoran Deserts, so it is adapted to local rainfall, soil and heat.