Skip to content Skip to left sidebar Skip to footer

Invasive weeds

Weeds and keeping control of them on your property is an ongoing chore when you’re a resident in the Waitakeres.

There is a community initiative the Waiatarua Weed Taskforce, a group of volunteers who work on each others property to help give some reprieved. If you would like to join this group and can actively participate a mininum of once every few months for an hour, contact: rita@waiatarua.org.nz to be added to the list.

Some advice:

  • Get a schedule going – the two times of the year that will require the most attention are spring and autumn – so put aside a weekend during both of these seasons to get on top of the emerging weeds.
  • You will need to then follow up with some further smaller weed control bursts – once every couple of months through the summer and winter.
  • At a bare minimum cut the tops off flowers (especially wild ginger)
  • Where you strip away weeds – don’t leave the area bare – plant natives they will block out light and make it harder for the weeds to grow back.
  • Be careful what you bring on to your property, mulch, straw, soil even borrowed machinery such as spades and wheelbarrows can all harbour weed seeds for species you may not have on your property.
  • Learn to enjoy it, its great physical exercise and can be very rewarding!

If you’re overwhelmed there is some help to get you on top of things, to a place where you can at least take the power back. Try the following for help:

 

Priority weeds

The most invasive weeds in the Waiatarua are below:

  1. Climbing asparagus
  2. Wild ginger
  3. Jasmine
  4. Tradescantia (Wandering Jew)

Weed types and how to control them

1. Ground Covers:

Plectranthus
The stand out feature is the slightly furry leaves are purple underneath. It reproduces by runners that creep along the ground forming thick mats, which
prevents new native seedlings from establishing, and will eventually thin out our
forests.

Getting rid of it isn’t too difficult, but the key is persistence! Hand pulling is easy, burn bury or securely dispose of the waste (be careful not to drop little bits of the plant as this can reproduce). If it is totally out of control or difficult to reach then herbicide may be an option, roundup will work on this one but you will have to add a penetrant to your sprayer. This weed is likely to come back so you will need to do a follow up every 3 months to keep on top of it.

The best long-term solution to preventing it coming back is to plant out the area
with something else. Being that it likes moist soil look for plants that like moist soils.

Also weed matting in the short term can also give you a bit of a breather!

  • Tradescantia
  • Wild Ginger
  • Agapanthus
  • African Club Moss
  • Mexican Daisy

2. Trees and Shrubs:

  • Tree privet
  • Woolley Nightshade
  • Monkey Apple
  • Bartlettina
  • Taiwan Cherry
  • Tutsan
  • Bungalow Palm

3. Creepers and Climbers

Climbing Asaparagus

Public enemy number one goes to this invasive and destructive weed. If there is one weed you don’t want on your property its Climbing Asparagus. Not only does it smother the forest floor, restricting new growth of natives, it can climb established natives and ring bark them – its especially fond of vulnerable species.

It is a delicate looking small fern like climber or scrambling perennial with tuberous roots. In spring it features white flowers which are followed by round berries (8mm diameter) that start green and ripen to orange. These berries are eaten and spread by birds (usually black birds).

You can get rid of it by staying vigilant: Dig out the tubers, these must be disposed somewhere they cant regrow, so the weed bins or burn them. If it has climbed up a tree, cut the vine at 30-60cm high and spray below the cut (the vegetation above will naturally die).  There are two times for spraying you can spray it in spring-early summer with glyphosate (roundup) 20m/L or autumn/winter (but not of frost days) with 10m/L of glyphosate – avoid runoff.

You will need to keep on top of this, the tubers are likely to resprout if they’re left in the ground, so any new growth will need to be continually sprayed until the tuber runs out of food or its dug out. You can also look to plant dense native ground covers.

There is plenty of help for this weed, if you’re overwhelmed by it press the panic button and contact
Weed Free Trust – info@weedfree.org.nz or
ph:09 8264 276.

  • Moth plant
  • Blue Morning Glory
  • Jasmine
  • Japanese Honeysuckle
  • Eleagnus

4. Open Areas

  • Gorse
  • Lantana
  • Blackberry
  • Ragwort
  • Heather
  • Crack Willow