# Milkweed in Pennsylvania

> 11 milkweed species are recorded in Pennsylvania.

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

## Overview

From the Allegheny Plateau to the Piedmont, Pennsylvania supports common, swamp, butterfly and poke milkweed, with purple milkweed clinging on in scattered woodland-edge sites. Powerline rights of way managed as meadow are among the state’s best monarch habitat.

- Species recorded: 11
- USDA hardiness zones: 5a–7b
- Monarch flyway: eastern
- Best time to sow seed outdoors: late October to early December

## Species recorded in Pennsylvania

| 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 |
| Purple Milkweed | Asclepias purpurascens | Yes | 2 ft–4 ft | May to July |
| Poke Milkweed | Asclepias exaltata | Yes | 3 ft–6 ft | June to July |
| 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 |
| Fourleaf Milkweed | Asclepias quadrifolia | Yes | 1 ft–2 ft | May to June |
| 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 |
| Red Milkweed | Asclepias rubra | Yes | 2 ft–4 ft | June to July |

## How to cite

Milkweed USA. (2026). Milkweed in Pennsylvania. https://milkweedusa.com/states/pennsylvania/