Plectranthus ecklonii, P. grandis

Blue spur flower

Family: Lamiaceae

Origin: Africa

Blue spur flower showing two flower heads and leaves.
Flowers are tubular and blue/ purple on erect purplish stems.

Regional Pest Management Plan (RPMP) status

  • Whole region — Sustained control
  • Hauraki Gulf Controlled Area Notice pest

View more about the RPMP statuses

General description

Soft-wooded shrubs < 2 m tall, strongly odorous. Stems are covered in short fine hairs. Leaves are oval, < 17 x 8 cm, hairy, dotted with sticky red glands and serrated. Flowers are small, tubular, blue/purple, and are borne in erect flowerheads <30cm tall in December – May. Nutlets are small and brown.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell blue spur flower within the Auckland region.
  • You must not plant blue spur flower within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property.
  • You must destroy any blue spur flower on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.

Habitats

Disturbed sites, forest margins, scrub.

Dispersal

Sets seed. Vegetative spread from runners and stem fragments. Human-mediated dispersal through soil movement and dumping of garden waste.

Impact on environment

Forms dense clumps, smothers and prevents establishment of native vegetation.

Control

Site Management

Follow up treated areas 3 times per 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.

Recommended approaches

Physical control

Method: Dig out.

Plant parts requiring disposal: All parts.

Disposal options: Compost in a composting weed bag or remove to greenwaste or landfill.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

No qualifications:

For small infestations: Cut stump and paste freshly cut base of stems with double strength glyphosate gel. Cut stems will resprout and will require disposal. Or foliar spray with 10ml glyphosate green per 1L of water.

Basic Growsafe certified:

For small infestations: Cut stump and spray freshly cut base with 250ml glyphosate green per 1L of water. Cut stems will resprout and will require disposal.

Certified Handler/Experienced agrichemical user:

For medium to large infestations: Foliar spray with 100ml glyphosate green per 10L of water and 20ml penetrant.

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

A bush of blue spur flower with large leaves and tall stalks of small purple flowers.
Blue spur flower forms dense stands out shading natives.
Photo credit: Top Tropicals.com
Blue spur flower in bloom.
Produces small brown nutlets.