Blue spur flower
Lamiaceae (mint) family
Also known as
Where is it originally from?
East and South Africa
What does it look like?
Erect shrub to 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 (up to 30 cm tall) produced from December to May are covered in small, tubular, purplish-blue violet flowers (10-15 mm long) which are followed by tiny brown nutlets.
Are there any similar species?
P. 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?
Easy to control.
1. Dig out (all year round). Dispose of at a refuse transfer station or burn or bury deeply.
2. Cut down and paint stump (all year round): glyphosate (200ml/L) or metsulfuron-methyl 600g/kg (1g/L) or triclopyr 600 EC (100ml/L) or triclopyr 120g/L (500ml/L).
3. Spray (all year round): glyphosate (10ml/L + penetrant) or metsulfuron-methyl 600g/kg (10g/100L + penetrant - spraygun) or (2g/10L + penetrant - knapsack)) or triclopyr 600 EC (30ml/10L) or triclopyr 120g/L (15ml/1L).
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.