Common Milkweed

Ecology & Conservation

Proximity Score

0

Native Status

✅ Outaouais ✅ Ottawa ✅ QC ✅ ON

Closest Direction

Local

CEC Eco-Regions

5 – Northern Forests, 5.2 – Mixed Wood Shield, 5.2.3 – Algonquin/Southern Laurentians

Rarity Notes

Globally secure (G5) with national rank N5 in both Canada and the United States. Ranked S5 in Ontario and S4 in Quebec. Not listed under SARA or COSEWIC. The species is abundant and widespread across its range, common in disturbed habitats.

S22 G5, N5 CA/US, S5 ON, S4 QC; S26 not SARA listed

Rarity Ranks

QC S4 – Apparently Secure, ON S5 – Secure

Migration

Stable

Ecological Context

Common milkweed is a characteristic colonizer of disturbed open habitats including old fields, roadsides, fence rows, and waste places throughout the Outaouais region. It thrives in dry to mesic sandy or loamy soils in full sun, forming large clonal patches via extensive rhizomes. In the Ottawa-Gatineau area it is common and widespread, documented from sandy roadsides, hydro corridors, and field margins. The species is an obligate larval host for Monarch butterflies and a critical nectar source for diverse pollinators.

S10 colonizer of disturbed areas; S4 old fields, roadsides, waste places; S7 dry to somewhat moist sandy areas; S62 Common in Ottawa; S54 Gatineau specimen from Hull

Permaculture & Companion Planting

Roles

Fortress/Barrier, Insectary Plant, Pollinator Attractor

S73/S29/S72 Evidence: Fortress/Barrier: S10 keyword match: prickl (supporting signal only); S61 keyword match: thorns? (supporting signal only)] | Insectary Plant: S64 NPPBI 'beneficial insects' flag] | Pollinator Attractor: S73 [HIGH]: S64 Xerces listed (source-classified)]

Notes

Common milkweed functions as a powerful pollinator attractor and insectary plant in guild design. Its abundant nectar draws long-tongued bees, wasps, butterflies, and moths. As the obligate Monarch larval host, it anchors butterfly garden guilds. Its aggressive rhizomatous spread should be considered in placement; best suited to meadow edges, hedgerows, or designated pollinator patches where its colonizing tendency is an asset rather than a liability.

S10 flowers very popular with many kinds of insects; S64 Xerces insectary plant + pollinator attractor; S29 weed potential noted; S4 colonizer of disturbed sites

Medicinal Properties

ℹ

Always consult a qualified healthcare provider before using any plant for medicinal purposes. The information provided is compiled from secondary sources for educational purposes only.

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Category

Analgesic, Contraceptive, Dermatological Aid, Diaphoretic, Diuretic, Emetic, Expectorant, Gastrointestinal Aid, Gynecological Aid, Kidney Aid, Laxative, Pulmonary Aid

S28 Moerman Drug categories; S29 PFAF medicinal uses

Notes

Root is anodyne, diaphoretic, diuretic, emetic, expectorant, and purgative, used historically for asthma, kidney stones, and venereal disease. The milky latex is applied topically to remove warts. Iroquois used root infusion as a contraceptive. Cherokee used root infusion for backache. Menominee used buds or root decoction for chest discomfort. Classified as an approved herbal name by Health Canada NHPID, with whole plant material authorized as a natural health product.

S28 22 Moerman drug uses; S29 PFAF medicinal; S36 Health Canada NHPID approved

Edibility & Foraging

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Never ingest a plant unless you have 100% certainty of its identity and have consulted multiple reputable sources. The information provided in the Localeaf Plant Database is compiled from secondary sources for educational and historical purposes only.

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✅ Edible   

Foraging Notes

Multiple parts are edible with proper preparation. Young shoots (less than 20 cm tall) are cooked as an asparagus substitute. Unopened flower buds are cooked like broccoli or peas. Young seed pods (2-4 cm) are cooked and resemble okra. Flowers can be boiled to make a brown sugar syrup. All parts require boiling to eliminate bitter taste and cardiac glycoside toxicity. Extensively used as food by Cherokee, Chippewa, Dakota, and Iroquois peoples.

S29 edible parts: flowers, leaves, shoots, seedpod, oil, seed; S28 21 Moerman food uses across multiple tribes; S4 requires careful boiling

Toxicity

⚠️ Moderate Toxicity

Contains cardiac glycosides (cardenolides) including asclepiadin, condurangin, and uzarigenin, primarily in the milky latex of stems and leaves. Older leaves are poisonous if eaten in large quantities. Toxic to livestock (sheep, cattle, horses) but generally avoided due to bitter taste. Not listed in Cornell poisonous plants database. The toxicity is the mechanism by which Monarch butterfly larvae acquire chemical defense against predators.

S29 cardiac glycosides, alkaloids, resinoids; S31 32 chemicals including cardenolides; S4 cardiac glycosides; S10 milky sap with cardiac glycosides