Posted on 17th August, 2016
It was during the very successful turnout of locals to pick up rubbish along the districts roadsides that a small group of us decided we would start trying to control some of the weeds invading our area.
There is absolutely no doubt that more and more weeds are making their way to the Tutukaka Coast and without intervention the situation will only get worse. According to D.o.C half of the 4,000 plant species growing in the wild have been introduced and over 70% of these were introduced to NZ as garden plants.
Every year another fourteen new exotic species become naturalised. When walking the road you can see how this can happen with garden waste including weeds dumped over the edge of the road almost anywhere a car can pull over.
Many trees are planted with the best intentions but are now spreading along the roadside threatening many native species, like the banksia trees north of Tutukaka.
Our mild climate, relative lack of natural diseases, animals and insects, makes the naturalisation of introduced plants easy. Northland one of the weediest areas in the world.
Being a small group of dedicated weeders who meet every few weekends on a Saturday afternoon we realise that we cannot control every weed in our district (maybe one day) but started with what we consider two of the worst, Moth vine and Ginger.
"Anyone who has been over the Helena Bay hill will know how damaging this plant is."
Araujia sericifera, also known by many common names e.g. moth vine, milk vine, cruel vine. This vine was introduced to NZ around 1880 and cultivated as a garden ornamental. It is a robust long-lived climbing plant reaching up to 10m, it can be found in many habitats from forest margins, roadsides, fences and often in waste areas or disturbed sites. The paired leaves and stems are greyish green. It grows in a twining fashion, rapidly smothering trees and shrubs. Bell shaped pinkish flowers occur from summer through to autumn. The seed pods are up to 150mm long and resemble a choko. A single pod can produce up to 1000 viable seeds. When a stem is snapped a milky sap appears which can cause allergic reactions.
Hedychium gardnerianun is also known as wild ginger or ginger lily, kahili ginger. Introduced into NZ in the 1890’s as a garden plant, wild ginger spread rapidly from the Waitakere ranges spreading to the north. This plant forms deep beds of dense many branched rhizomes. Growing 2 metres in height the green shiny stems have no branches, alternate lance-shaped leaves producing flower heads up to 450mm tall with fragrant lemon yellow-flowers and red stamens in autumn. Long lived and fast growing, it forms thick rhizome beds letting nothing grow through its mat of tubers that smother other plants. Anyone who has been over the Helena Bay hill will know how damaging this plant is.
Already our group has located a number of moth vine sites, removing hundreds of pods. All sites are recorded so regular visits can be made to kill regenerating plants or seedlings. We believe that although the Tutukaka Coast is very weedy these two weeds which are not yet here in big numbers may be possible to control. We need your help in locating more sites of the moth vine and ginger plants. If you know of any or need help to remove them contact Tawapou Coastal Natives (027 2896827)