Blue spur flower
Botanical Name
Plectranthus ecklonii
Family
Lamiaceae (mint)
Also known as
Plectranthus
Where is it originally from?
East and South Africa
What does it look like?
Erect shrub (<2-3 m tall) with young stems covered in short, fine hairs. Oval leaves (6-17 x 3-8 cm) are covered with short fine hairs and dotted with red glands above and below, and are irregularly serrated along the edges. Loose, erect, flowerheads (<30 cm tall) covered in small, tubular, purplish-blue violet flowers (10-15 mm long) appear from December to May, and are followed by tiny brown nutlets.
Are there any similar species?
Plectranthus grandis is hairy and has blue flowers. P mahonii is also similar.
Why is it weedy?
Moderately long-lived and tolerates semi-shade, damp, and high to moderate temperatures.
How does it spread?
Produces few seeds, with most new plants forming from stem fragments spread during soil movement and vegetation dumping.
What damage does it do?
Forms dense stands, prevents the establishment of native plant seedlings and can lead to subsequent invasion of infested areas by weedy vines.
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. Physical removal - Hand pull small plants, or dig out entire plant including roots (all year round): Dispose of at a refuse transfer station, burn, or bury deeply.
2. Cut and paste (all year round) - Cut the stem/trunk as close to the ground as possible and cover the entire stump with herbicide as soon as possible after cutting. Apply either glyphosate gel (120g/L strength) or metsulfuron gel (10g/l strength) or picloram gel (43g/l strength) to the entire cut stem.
4. Foliar spray - Apply Glyphosate (360 g/L active ingredient) herbicide (20ml/L) plus organosilicone penetrant (2ml/L) to cover entire plant Note: Non selective. Avoid overspray onto desirable plants. OR Apply Metsulfuron herbicide (600g/kg active ingredient) (Knapsack 0.5g/L, or Gun and hose 20-35g/100L) plus organosilicone penetrant (3ml/L) to thoroughly wet all parts of plant. Note: Metsulfuron overspray will kill other (desirable) broadleaf plants and has residual activity in the soil which aids in killing below ground parts.
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?
Cut stems resprout. Follow up within 3-6 months to kill resprouted stems. Replant bare sites.
Images
