What does it look like?
Blue morning glory has climbing vine with tough, hairy, twining, stems. It has tough fibrous roots without rhizomes. Leaves (5-18 x 5-16 cm) are usually 3-lobed (trumpet-shaped) and silky-hairy underneath.
From late spring to early winter, groups of 3-12 deep blue-purple flowers that are pink at the base and wither in the midday sun are produced. Little or no seed is produced in New Zealand, so this plant is spread almost entirely by garden dumping and spreading from the affected area.
Why is it a problem?
Blue morning glory grows at a fast rate and tolerates a wide range of conditions from hot to cool, damp to dry. It does particularly well near water or in high humidity/rainfall areas. Its dense smothering habit and ability to climb to the top of the forest canopy makes it the dominant vine wherever it occurs, and it will ultimately kill the plants it covers. This results in forest replaced with a low weedy blanket.
Control methods
Physical control
Hand-pull small plants any time of year, ensuring all stem and root fragments are dug out. Dispose of roots at a refuse transfer station. Ensure any vine matter left behind is not in contact with the ground, as these can re-root and form a new plant.
Herbicide control
Cut down and paint stump (all year round) with Gyphosate (100ml/L) or metsulfuron-methyl 600g/kg (1g/L). Or
Cut vines at waist height (summer-autumn) and spray foliage below with Glyphosate (10ml/L + penetrant) or metsulfuron-methyl 600g/kg (2g/10L + penetrant (knapsack) or 20g/100L + penetrant (spraygun).
Follow up to check that slashed stems have not resprouted.
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.
Related links
Management Programme
National Pest Plant Accord
All plants on MPI's National Pest Plant Accord (NPPA) are unwanted organisms under the Biosecurity Act 1993 whose formal or casual trade contributes significantly to their spread.
Plants on the Accord cannot legally be propagated, distributed, or sold in New Zealand. If allowed to spread further, these pest plants could seriously damage our economy and environment.
Unwanted Organism
An unwanted organism is any organism that's capable of causing harm to natural or physical resources (like forests and waterways) or human health. A number of introduced pests in New Zealand are classed as unwanted.
More informationOrganism of Interest (OOI)
Organisms Of Interest (OOI) are those specified as pests under our Regional Pest Management Plan that are capable of causing significant adverse effects on one or several of our Regional values. These species warrant being watch-listed for ongoing surveillance or future control opportunities.
More informationTaxonomies
FamilyConvolvulaceae
TypePlants
GroupClimber
HabitatLand
Management ProgrammeNational Pest Plant AccordUnwanted OrganismOrganism of Interest (OOI)
