How to get rid of moth plant
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Moth plant may have pretty flowers, but it’s considered a serious pest plant in many parts of New Zealand. Originally from South America, it was introduced as an ornamental plant — valued for its fast growth and climbing ability — but has since become invasive. It grows aggressively and can smother backyards, parks and native forests by climbing and spreading rapidly.
What you can do
If you spot a moth plant in your garden or local area, it’s actually easiest to control it when it produces its white or pink flowers in early summer. The flowers make the plant easy to spot, and if you dig up the plant then, you won’t have to spend time removing the pods.
Once pods have formed, it’s important to kill the plant and remove the pods before its seed pods burst. Each pod contains up to one thousand fluffy seeds that can be easily carried by the wind, allowing this invasive vine to spread rapidly. If left unchecked, moth plants can smother native vegetation and disrupt local ecosystems. Early removal makes a big difference — here’s how to safely and effectively get rid of them.
Keeping yourself safe
Moth plant contains a white milky sap that’s poisonous and an irritant for the skin and eyes, so make sure kids and pets don’t play with the pods. The sap can also leave stains on clothing.
When dealing with moth plant, we recommend being prepared by:
- Wearing long-sleeves (preferably old clothes) and gloves
- Wearing eye protection
- Bringing a sack or bag to contain the pods
Here’s how Mel from our Nature Team gets ready to handle moth plant:
Controlling young moth plants
Even if the plant hasn’t developed pods, you can identify them by their opposite, dark green, pointy leaves, and white sap when you break a leaf off. Small plants can be pulled up by the root. Watch how Mel does this below.
Controlling larger moth plants
Larger moth plants can be dug up with a spade, or for those who feel comfortable using herbicide, Auckland Council recommends cutting the stump and pasting freshly cut base of stems with metsulfuron gel. This will ensure the plant doesn’t grow back, although it’s a good idea to revisit the site for the following two to three years to see if new plants have grown from seed. Watch how Pam uses MetGel to kill a moth plant below.
CAUTION: When using any herbicide, please read the label carefully and follow instructions for its use and storage.
Removing moth plant pods
Pod season typically runs from late summer to autumn, and each pod contains up to a thousand seeds that can be carried by the wind. Once pods have developed, it becomes a race against time to remove and dispose of them before they burst. Luckily, removing the pods is pretty easy. Sometimes you can even win prizes for collecting pods and removing vines in Auckland, such as in the Henderson-Massey Moth Plant Competition. Watch how Mel removes pods in the video below.
To make sure that the pods you’ve collected don’t spread their seeds, it’s important not to dispose of them in a home compost bin. Bag them up and put them in a landfill bin instead, or if you live close to the Waitākere Ranges, you can dispose of them at a Weed Bin Weekend.
Find out more
Auckland Council’s Tiaki Tāmaki Makaurau website contains helpful information on identifying and removing moth plant.
The Weedbusters website has great photos of moth plant through the seasons.
Join the Society Totally Against Moth Plant (STAMP) Facebook group to connect with others in New Zealand on a mission to get rid of moth plant.
