Whorled Milkweed

Asclepias verticillata

Native to:
Canada, United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Apocynaceae
Genus:
Asclepias
Species:
Asclepias verticillata
USDA Symbol:
ASVE

Growth Characteristics

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

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Butterflies & Moths:
★☆☆☆☆ Documented Lepidoptera association (GBIF)
Caterpillars:
★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)

Keystone Species Ranking

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

Host Plant for Caterpillars

⚠️Monarch butterfly (Danaus plexippus)

Reported Fauna Sightings

Bees: Martinapis luteicornis, Southern plains bumble bee (Bombus fraternus) Moths:Cycnia collaris Butterflies:Black Swallowtail (Papilio polyxenes), Carus Skipper (Polites carus), Gray Hairstreak (Strymon melinus), ⚠️Monarch butterfly (Danaus plexippus), Orange Sulphur (Colias eurytheme), Queen butterfly (Danaus gilippus)

Garden & Ecology Notes

Wildlife Value:
butterflies, bees, monarch butterflies
Deer Resistant:
Yes
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Resprouts vigorously from deep taproots after fire. Common component of fire-maintained prairie 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:
prefers open, sunny habitats

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
7–21 days
Notes:
Seeds benefit from cold moist stratification. Light exposure during germination may improve success rates.

The above propagation data sourced from Claude AI

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

Source: Claude AI

ORGHPS Germination Guide: Expose to fluctuating outdoor winter temps incl. freezing for 3 months. Increase light/temp in spring.

Source: Ontario Rock Garden & Hardy Plant Society