# Hall’s Milkweed (Asclepias hallii)

> A handsome southern Rocky Mountain endemic with soft pink-mauve flower clusters and grayish lance-shaped leaves, growing on dry mesas, sandy foothills and piñon-juniper edges from Colorado to Nevada.

Source: https://milkweedusa.com/species/halls-milkweed/  
Licence: CC BY 4.0 (Milkweed USA)

## Summary

A handsome southern Rocky Mountain endemic with soft pink-mauve flower clusters and grayish lance-shaped leaves, growing on dry mesas, sandy foothills and piñon-juniper edges from Colorado to Nevada.

## Key facts

| Field | Value |
| --- | --- |
| Scientific name | Asclepias hallii A. Gray |
| Genus | Asclepias |
| Family | Apocynaceae |
| Common names | Hall’s Milkweed, Purple Silkweed |
| Status | Native |
| Height | 1.5 ft–3 ft |
| Spread | 1.5 ft–3 ft |
| Flower color | pink, mauve |
| Bloom period | June to August |
| Light | Full sun |
| Soil moisture | Dry |
| USDA zones | 4-8 |
| Leaf arrangement | opposite |
| Leaf shape | lanceolate |
| Sap | Milky latex |
| Root system | Rhizomatous, spreads by root |
| Seed stratification | 30 days cold-moist |
| Monarch value (0-5) | 4 |
| Garden value (0-5) | 3 |
| Nectar value (0-5) | 4 |
| US states recorded | Arizona, Colorado, New Mexico, Nevada, Utah, Wyoming |

## Identification

- Resembles a slimmer, drier-country showy milkweed with narrower leaves and smaller flowers.
- Flower clusters are terminal and upright, pale pink to dull rose.
- Stems often several from a spreading rootstock, sometimes forming loose colonies.

## Ecology

A significant monarch host on Colorado’s Western Slope and across the Colorado Plateau, where large-leaved milkweeds are scarce.

## Growing

Excellent for xeric gardens in the Interior West, though seed is hard to source. Needs sharp drainage and full sun.

## Cautions

Standard milkweed cautions.

## References

- Plants of the World Online: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:94337-1
- GBIF: https://www.gbif.org/species/3170237
- iNaturalist: https://www.inaturalist.org/taxa/158741
- BONAP county map: https://bonap.net/MapGallery/County/Asclepias%20hallii.png
- NatureServe: https://explorer.natureserve.org/Search?searchTerm=Asclepias%20hallii

## Photographs

- Fort Bayard - Flickr - aspidoscelis (20) (Patrick Alexander from Las Cruces, NM, CC0): https://commons.wikimedia.org/wiki/File:Fort_Bayard_-_Flickr_-_aspidoscelis_(20).jpg
- Near Border Hill - Flickr - aspidoscelis (Patrick Alexander from Las Cruces, NM, CC0): https://commons.wikimedia.org/wiki/File:Near_Border_Hill_-_Flickr_-_aspidoscelis.jpg
- Fort Stanton Mesa - Flickr - aspidoscelis (Patrick Alexander from Las Cruces, NM, CC0): https://commons.wikimedia.org/wiki/File:Fort_Stanton_Mesa_-_Flickr_-_aspidoscelis.jpg
- Near Ft. Stanton - Flickr - aspidoscelis (4) (Patrick Alexander from Las Cruces, NM, CC0): https://commons.wikimedia.org/wiki/File:Near_Ft._Stanton_-_Flickr_-_aspidoscelis_(4).jpg
- Hall’s Milkweed photographed in Colorado, US (Ryan Sorrells, CC BY 4.0): https://www.inaturalist.org/observations/229442566
- Hall’s Milkweed photographed in Chaffee County, US-CO, US (Public domain (CC0), CC0): https://www.inaturalist.org/observations/30958195
- Hall’s Milkweed photographed in Fremont County, CO, USA (Anders Hastings, CC BY 4.0): https://www.inaturalist.org/observations/294085062
- Hall’s Milkweed photographed in Arkansas River Trail, Buena Vista, CO, US (Brad Grimm, CC BY 4.0): https://www.inaturalist.org/observations/293208490

## How to cite

Milkweed USA. (2026). Hall’s Milkweed (Asclepias hallii). https://milkweedusa.com/species/halls-milkweed/