Indian hemp.

At a glance

Care level

Easy

Plant type

Perennial

Light

Full sun

Indoor light

Direct sun

Water

Every 7 to 14 days

Mature size

3 to 5 feet

Growth rate

Fast

Hardiness

USDA 3 to 9

Bloom time

Mid to late summer

Care

Plant this in a spot with plenty of sun and well draining soil. Watch for aggressive spreading, as it can quickly take over a garden bed. It is quite drought tolerant once it is established.

Watering

Water deeply once the top few inches of soil feel dry to the touch.

Feeding

A light application of balanced fertilizer in early spring is plenty.

Pruning

Cut the stems back to the ground in late autumn after the foliage dies back.

Repotting

If growing in a container, move to a larger pot every few years to accommodate its vigorous root system.

Soil

Well draining sandy or loamy soil

Soil pH

6.0 to 7.5

Temperature

-30 to 35°C

Humidity

30 to 70%

Safety

People

All parts of the plant contain cardiac glycosides that can cause severe illness or death if ingested.

Pets

This plant is toxic to cats and dogs if ingested due to cardiac glycosides.

Children

Keep this plant away from children as all parts are toxic and the milky sap is an irritant.

Contact allergens

The milky sap can cause skin irritation or dermatitis in sensitive individuals.

Airborne allergens

The pollen may cause mild respiratory irritation for those with severe allergies.

Edibility

This plant is highly toxic if ingested and should never be consumed.

How to identify it

• Opposite lance shaped leaves
• Small white bell shaped flowers
• Milky white sap in stems
• Long slender seed pods
• Reddish stems on mature plants

Height

0.6 to 1.5m

Spread

0.3 to 0.9m

Leaves

green, deciduous

Flowers

white, greenish-white, 0.5 to 1cm

Fruit

brown, Autumn

Problems to watch for

• AphidsCommon
• Milkweed BugsCommon
• DehydrationUncommon
• Leaf SpotUncommon
• Root RotUncommon
• RustUncommon

Growing it

Propagation

division, seed, rhizome cuttings

When to plant

Spring, Autumn

Plant this in a contained area or a wild meadow space to prevent it from overtaking smaller, less vigorous perennials.

Grows well with

• Common Milkweed · They share similar habitat requirements and both support monarch butterflies.
• Goldenrod · These provide a late season nectar source that complements the dogbane bloom.

Similar species

• Spreading Dogbane · It is a closely related species with similar growth habits and toxic properties.

Science

Family

Apocynaceae

Genus

Apocynum

Order

Gentianales

Class

Magnoliopsida

Native range

Widespread across North America.

Conservation

This plant is common and widespread across its native range and is not of conservation concern.

It thrives in open fields, meadows, and disturbed sites by utilizing its deep rhizomes to outcompete other vegetation.

Value to wildlife

nectar source, larval host plant

Pollinators

bees, butterflies, moths, beetles

Uses

pollinator garden, native restoration, fiber source

Taxonomy resolved against GBIF.

Questions people ask

Is dogbane invasive?

It is native to North America but can be very aggressive in garden settings due to its rhizomes.

Does it need full sun?

Yes, it performs best in full sun to partial shade.

Where the name comes from

The genus name Apocynum comes from Greek words meaning away and dog, reflecting its reputation as a dog poison. The specific epithet cannabinum refers to the hemp-like fibers found in the stem.

Good to know

• Native Americans historically used the strong fibers from the stems to make cordage and fishing nets.
• The plant spreads aggressively through an extensive underground rhizome system.
• It is a primary larval host for the snowberry clearwing moth.
• The flowers are known to trap small insects that are not strong enough to escape.

Also in

• Plants toxic to cats and dogs