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What Are Weeds?

Weed Information Sheet

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Blue spur flower

Botanical Name

Coleus barbatus Var. grandis

Family

Lamiaceae (mint)

Also known as

Plectranthus grandis

Where is it originally from?

East and South Africa

What does it look like?

Soft-wooded, strong-smelling upright shrub (<2-3 m tall). Large, downy, soft, broad (6-20 x 4-13 cm), oval leaves with coarsely toothed edges and rounded tips with small sticky glands on underside. Tubular deep blue flowers (20-25 mm long) in whorls of 4-10 (Jan-Dec), on erect purplish stems (20-50 cm tall), are followed by tiny brown nutlets (May).

Are there any similar species?

Plectranthus ecklonii has purplish-blue flowers, is less woolly. P. barbatus.

Why is it weedy?

Tolerates semi-shade, damp, and high to moderate temperatures, but is frost tender. Moderately long-lived.

How does it spread?

Produces few seeds, spreading mainly by stem fragments through soil movement and dumping of garden waste.

What damage does it do?

Forms dense stands, stopping native plants from establishing. Shades out smaller native plants and scrambles over other plants. Dense growth can restrict access to bush areas.

Which habitats is it likely to invade?

Heavily disturbed bush and shrubland, and bush margins, especially in northern areas.

What can I do to get rid of it?

1. Dig out small patches (all year round): dispose of at refuse transfer station, burn or bury.
2. Cut trunk and paint stump (all year round): cut trunk near to the ground, and swab freshly cut stump with metsulfuron-methyl 600g/kg (1g/L) or glyphosate (200ml/L) or triclopyr 600g/L (100ml/L).
3. Overall spray (all year round): metsulfuron-methyl 600g/kg (2g/10L) + penetrant; or glyphosate (100ml/L) + penetrant or triclopyr 600g/L (30ml/10L).

CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and directions for the purchase, use and storage of the product, are followed and adhered to.

What can I do to stop it coming back?

Easy to control. Follow up within 3-6 months to kill resprouted stems. Replant bare sites.

Images

Photo: Trevor James
Photo: Trevor James
Photo: Carolyn Lewis
Photo: Trevor James
Photo: Trevor James
Photo: Trevor James
Photo: Trevor James
Photo: Trevor James

Download PDF Information Sheet

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  • Home
  • Weedbusters
    • Who are Weedbusters?
  • What Are Weeds?
    • Weed List
    • Controlling Weeds
      • Controlling Pest Shrubs & Trees
      • Controlling Pest Vines
      • Controlling Pest Herbs & Ground Covers
      • Controlling Pest Grasses
      • Controlling Pest Aquatic Weeds
    • Disposing of Weed Waste
    • Banned Plants
  • Get Involved
    • Become a Weedbuster
    • Weedbusters Near You
    • Weed Quiz
  • Resources
    • How to…
      • Raise Weeds Awareness
      • Organise a Weedbusters Event
    • Weedbusting Guide
    • Plant Me Instead Booklet
    • Using Weedbuster photographs
    • Useful Links
  • Contact Us
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