Dogbane

Apocynum cannabinum

Dogbane/Indian Hemp (Apocynum cannabinum) is a native North American perennial with small summer flowers and a clumping habit. It tolerates poor soils and spreads by seed and rhizomes but is toxic if ingested.

Key Facts

  • Native North American perennial in the dogbane family
  • Usually grows as an upright clump from rhizomes
  • Flowers are small greenish to pinkish and bloom in summer
  • Spreads by seed and by underground rhizomes
  • Tolerates poor, dry to medium soils and sandy or rocky sites
  • Prefers full sun to part shade
  • Contains toxic compounds and is poisonous to livestock and pets
  • Used historically by Indigenous peoples for cordage from the stems

Dogbane/Indian Hemp (Apocynum cannabinum) is a native North American perennial that forms upright clumps and produces small greenish to pinkish flowers in summer. It tolerates poor dry to medium soils and spreads both by seed and by underground rhizomes, but all parts are poisonous if eaten.

Identification

This plant typically reaches 2 to 4 feet tall with a 1 to 3 foot spread and bears clusters of small greenish to pinkish flowers in summer, generally June through August in the Northern Hemisphere. Stems arise from rhizomes and seed pods release silky haired seeds that can travel on the wind.

Best uses and where to grow

Use dogbane in native plantings or prairie edges where a tough, low maintenance clump is wanted and its toxicity is not a concern. It performs best in full sun but will tolerate part shade and is suited to well drained dry to medium soils including sandy or rocky sites.

Planting and spacing

Plant divisions in spring or fall to establish clumps, or start from seed in disturbed ground where seedlings can take hold. Space plants roughly 1 to 3 feet apart to allow natural clump growth and to reduce competition as rhizomes expand.

Watering and care

Once established this species needs little supplemental water on well drained sites and will decline in waterlogged soil. Overly wet conditions can cause crown rot or reduced vigor while plants in shade may grow taller with fewer flowers.

After flowering and maintenance

Leave some seedheads if you want it to naturalize, or cut back flower stems before seed set to reduce wind dispersed seedlings. To split or move clumps divide rhizomes in spring or fall. Pull or dig up young seedlings and remove rhizome pieces to keep it contained.

Spread and control

Spread occurs by wind dispersed seed and by rhizomes. Expect loose colonies in favorable sites. Control options include cutting before seeds form, removing rhizomes with a spade, and monitoring for seedlings in disturbed soil.

Toxicity and safety

All parts of the plant contain toxic compounds and can be poisonous to livestock, pets and people if ingested. The sap may irritate skin. Keep animals away from stands and consult local extension or poison control for specific emergency guidance.

Frequently asked questions

How fast does Dogbane/Indian Hemp grow?
Plants commonly reach their 2 to 4 foot height within a growing season and can form colonies over time as rhizomes spread and seedlings establish.
Is Dogbane/Indian Hemp poisonous to pets and livestock?
Yes. All parts are considered toxic if ingested and the sap can be an irritant. Confirm risks and emergency steps with local extension or poison control.
Can this plant be used for cordage or fiber?
Historically Indigenous peoples used the stems for cordage. That traditional use is part of the species record but handle stems carefully because of the plant’s toxicity.
When is the best time to plant or divide it?
Divide clumps in spring or fall. Seedlings are most likely to establish in disturbed ground when seeds are present after summer flowering.
Will it grow in shade?
It tolerates part shade but flowers best in full sun. In shade plants tend to be taller and produce fewer blooms.

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