Datura stramonium

Thornapple

Also known as:

Jimsonweed

Family: Solanaceae

Origin: Central and South America

A field of Thornapple on a hillside.
An upright annual herb that grows up to 2m tall. Thornapple is foul smelling and bears large white, trumpet-like flowers from Spring to Autumn.
Photo credit: Jonathan Boow

Regional Pest Management Plan (RPMP) status

  • Not a legally declared pest

View more about the RPMP statuses

General description

Erect, foul-smelling annual herb < 2 m tall. Stems are stout, smooth and green to reddish. Leaves are broad, toothed and alternate. Flowers are large, white, trumpet-shaped and borne in November – April. Fruits are egg-shaped, usually spiny, four-chambered and contain flat, kidney-shaped seeds.

What you need to know

Although thornapple is not a legally declared pest plant, it may still be invasive in some situations. Consider lower-risk alternatives for your garden, such as native plants.

Habitats

Disturbed sites, riparian margins, pasture, gardens, wasteland, roadsides.

Dispersal

Seeds dispersed by birds, gravity and attachment to animal coats.

Impact on environment

Reduces crop yield. Toxic to humans and animals.

Control

Site Management

Follow up treated areas each year. Encourage natural regeneration of native plants or replant treated areas where possible after 2-3 treatments to establish dense ground cover and minimise reinvasion. Other herbicides are available for selective use in pasture.

Recommended approaches

Physical control

Method: Dig out.

Plant parts requiring disposal: Seed heads if practical.

Disposal options: Remove to greenwaste or landfill if practical.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

No qualifications: Cut stump and paste freshly cut base of stems with double strength glyphosate gel.

Basic Growsafe certified: Cut stump and spray freshly cut base with 250ml glyphosate green per 1L of water.

Certified Handler/Experienced agrichemical user: Foliar spray with 60ml triclopyr per 10 Litres of water and 20ml penetrant in spring or summer.

Safety notes

Plant has thorns. Plant is poisonous to humans and animals.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Close up of Thornapple seed capsule opening.
Once pollinated, thornapple flowers form into small egg-shaped seed capsules that are brown and spiky. As they mature they dry out, and the tip of the seed capsule peels back forming an opening for seeds to fall out.
Photo credit: Jonathan Boow
An immature Thorn Apple seed capsule.
Thornapple is not declared a pest plant in Auckland but has the potential to become weedy. Seeds are spread by gravity and can germinate close to the parent plant creating dense stands.
Photo credit: Jonathan Boow