# Milkweed in Wyoming

> 14 milkweed species are recorded in Wyoming.

Source: https://milkweedusa.com/states/wyoming/  
Licence: CC BY 4.0 (Milkweed USA)

## Overview

Showy milkweed follows the North Platte, Bighorn and Green River corridors, and the state’s shortgrass plains hold plains, green comet and Engelmann’s milkweed. Wyoming straddles the eastern and western monarch flyways and its riparian ribbons carry nearly all the breeding.

- Species recorded: 14
- USDA hardiness zones: 2b–6a
- Monarch flyway: both
- Best time to sow seed outdoors: September to November, before the ground freezes

## Species recorded in Wyoming

| Common name | Scientific name | Native | Height | Bloom |
| --- | --- | --- | --- | --- |
| Swamp Milkweed | Asclepias incarnata | Yes | 3 ft–5 ft | June to September |
| Butterfly Weed | Asclepias tuberosa | Yes | 1 ft–3 ft | May to September |
| Showy Milkweed | Asclepias speciosa | Yes | 2 ft–5 ft | May to August |
| Common Milkweed | Asclepias syriaca | Yes | 3 ft–6 ft | June to August |
| Whorled Milkweed | Asclepias verticillata | Yes | 1 ft–2.5 ft | June to September |
| Hall’s Milkweed | Asclepias hallii | Yes | 1.5 ft–3 ft | June to August |
| Green Comet Milkweed | Asclepias viridiflora | Yes | 1 ft–3 ft | May to August |
| Broadleaf Milkweed | Asclepias latifolia | Yes | 1 ft–3 ft | May to August |
| Plains Milkweed | Asclepias pumila | Yes | 4 in–1 ft | June to September |
| Engelmann’s Milkweed | Asclepias engelmanniana | Yes | 2 ft–5 ft | June to August |
| Slimleaf Milkweed | Asclepias stenophylla | Yes | 1.5 ft–3.3 ft | June to August |
| Poison Milkweed | Asclepias subverticillata | Yes | 1 ft–3 ft | June to September |
| Pallid Milkweed | Asclepias cryptoceras | Yes | 4 in–1 ft | April to June |
| Wheel Milkweed | Asclepias uncialis | Yes | 2 in–6 in | April to June |

## How to cite

Milkweed USA. (2026). Milkweed in Wyoming. https://milkweedusa.com/states/wyoming/