Arizona Milkweed

Asclepias angustifolia

Native to:
Mexico, United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Apocynaceae
Genus:
Asclepias
Species:
Asclepias angustifolia
USDA Symbol:
ASAN5

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb
Height:
90 cm
Light Requirements:
Full Sun,Part Shade
Drought Tolerance:
High
Bloom Months:
may,jun,jul,aug
Bloom Colors:
greenish-white, cream, pink

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

Butterflies:⚠️Monarch butterfly (Danaus plexippus), Queen butterfly (Danaus gilippus)

Garden & Ecology Notes

Wildlife Value:
bees, butterflies, Monarch butterflies
Deer Resistant:
Yes
Fragrant:
Yes
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Resprouts vigorously from deep rootstock after fire. Common in fire-maintained grassland ecosystems.

Soil Requirements

Soil Type:
sandy, well-drained, nutrient-poor soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to arid and semi-arid regions

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
7–21 days
Notes:
Seeds germinate best with light exposure. Fresh seed germinates more readily than stored seed.

The above propagation data sourced from Claude AI

Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).

Source: Claude AI

ORGHPS Germination Guide: Should not need chilling

Source: Ontario Rock Garden & Hardy Plant Society