Ipomea indica

Blue Morning glory is showing its true colours this summer

This invasive climber was once a garden plant and with its bright deep blue flowers. Now this climber, like many others that have ‘jumped the fence’, is a killer! Its growth can quickly kill new plants as well as established trees. This means our native forests, like the Piroa-Bryderwyns directly threat from these invaders.

Blue morning glory is moved around by people and machinery. Sometimes this is deliberate – illegal in New Zealand under the National Pest Plant Accord – but often as pieces on dirty earth moving machinery.  

Some invasive climbers (like mignonette vine) are very hard to eradicate but blue morning glory is easier as it doesn’t usually have seeds. However, any small piece can potentially grow and reinvade.  Cutting the vine off at knee height will kill all the upper parts in the tree. A hedge cutter can be useful for this. Then allow it to resprout. The new leaves will absorb the herbicide and kill the underground stems and roots. Then it is a matter of checking over the next 6 months to ensure it has all died

Hand removal is always best for the environment but sometimes this can be very slow and time-consuming process. Because the leaves are quite hairy, any herbicide used needs to have a penetrant added and at double strength. This can be dish-liquid – at 2ml per litre of mix for small jobs. For larger tasks, it is recommended to get the appropriate penetrant recommended by the herbicide manufacturer. Any herbicide with the active ingredient as either glyphosate or triclopyr will work. Use at gorse rates.

For more information on Weed Action Piroa-Bryderwyns contact Sara Brill on 0220104092 or visit our webpage via www.weedaction.org.nz