Rush Milkweed

Asclepias subulata

Native to:
Mexico, United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Apocynaceae
Genus:
Asclepias
Species:
Asclepias subulata
USDA Symbol:
ASSU

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb , Subshrub
Height:
120 cm
Light Requirements:
Full Sun
Drought Tolerance:
High
Bloom Months:
mar,apr,may,jun,jul,aug,sep
Bloom Colors:
white, cream, yellow
Landscaping Shrub:
Yes

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Butterflies & Moths:
★☆☆☆☆ Documented Lepidoptera association (GBIF)

Keystone Species Ranking

Caterpillar Keystone:
★★☆☆☆ Butterfly & moth species supported by this genus (NWF)

Reported Fauna Sightings

Bees: ⚠️Western honey bee (Apis mellifera) Butterflies:Gray Hairstreak (Strymon melinus), ⚠️Monarch butterfly (Danaus plexippus), Queen butterfly (Danaus gilippus)

Garden & Ecology Notes

Wildlife Value:
monarch butterflies, native bees, hummingbirds
Deer Resistant:
Yes
Fragrant:
Yes

Soil Requirements

Soil Type:
well-drained, sandy or gravelly soil
pH:
6.0 - 8.0 (neutral to slightly alkaline)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to arid desert regions

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
7–21 days
Notes:
Seeds require light for germination. Sow on surface and keep warm (70-75°F). Fresh seed germinates more readily than stored seed.

The above propagation data sourced from Claude AI

Pre-treatment: Single-step cold-moist stratification for temperate woodland species. for 60–120 days

Notes: Seeds germinate readily without pretreatment.

Source: Claude AI

ORGHPS Germination Guide: Should not need chilling

Source: Ontario Rock Garden & Hardy Plant Society