# Milkweed in Oklahoma

> 23 milkweed species are recorded in Oklahoma.

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

## Overview

Oklahoma sits squarely in the central flyway funnel, with green antelopehorn and antelope horns on the prairies, sand milkweed in the dune country and swamp milkweed along the eastern rivers. The state is a spring and fall bottleneck for the whole eastern population.

- Species recorded: 23
- USDA hardiness zones: 6a–8a
- Monarch flyway: eastern
- Best time to sow seed outdoors: October to November

## Species recorded in Oklahoma

| 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 |
| Prairie Milkweed | Asclepias sullivantii | Yes | 2 ft–4 ft | June to July |
| Purple Milkweed | Asclepias purpurascens | Yes | 2 ft–4 ft | May to July |
| Antelope Horns | Asclepias asperula | Yes | 1 ft–2 ft | March to July |
| Green Antelopehorn | Asclepias viridis | Yes | 1 ft–2.5 ft | April to July |
| Aquatic Milkweed | Asclepias perennis | Yes | 1 ft–3 ft | May to September |
| Zizotes Milkweed | Asclepias oenotheroides | Yes | 8 in–2 ft | March to October |
| 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 |
| Clasping Milkweed | Asclepias amplexicaulis | Yes | 1.5 ft–3 ft | May to July |
| White Milkweed | Asclepias variegata | Yes | 1.5 ft–3.5 ft | May to July |
| 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 |
| Sand Milkweed | Asclepias arenaria | Yes | 1 ft–2.5 ft | June to August |
| Red Milkweed | Asclepias rubra | Yes | 2 ft–4 ft | June to July |
| 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 |
| Tall Green Milkweed | Asclepias hirtella | Yes | 2 ft–4 ft | June to August |
| Poison Milkweed | Asclepias subverticillata | Yes | 1 ft–3 ft | June to September |
| Dwarf Milkweed | Asclepias involucrata | Yes | 4 in–10 in | April to June |

## How to cite

Milkweed USA. (2026). Milkweed in Oklahoma. https://milkweedusa.com/states/oklahoma/