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African Weed Orchid Alert in Marengo

First detected at Marengo Airfield in 2015, it is the only known case in the Otway area. Adjacent to the Airfield is the ecologically significant Marengo Conservation Reserve.

Native to South Africa, the African Weed Orchid is considered to be a significant environmental weed in Victoria. As it hasn't spread through the Otway Region, it is a high priority to eradicate it wherever it is located. The noxious orchid out-competes native ground cover species displacing desirable native orchid and grass species. The tiny dust-like seeds are easily dispersed by wind, animals and equipment and spread the infestation. The perennial tubers also support the emergence of new plants each year. Its location on the airfield poses an increasing threat to our Marengo Nature Conservation Reserve, specifically to the native orchids and wildflowers that it is capable of outcompeting.

Over the last few years the Southern Otway Landcare Network has been working with their project partners, Parks Victoria and the Colac Otway Shire, with funding from the Victorian Department of Environment, Land, Water and Planning to help protect the Marengo Nature Conservation Reserve from the threat of African Weed Orchid.

The African Weed Orchid in flower.


The infestation in the airfield was surveyed and treated by digging plants out in spring 2018. The Colac Otway Shire have changed their slashing schedule to avoid dispersal of seed while the Weed Orchid is in flower. Information about the threat has been provided to landholders adjacent to the Reserve. The infestation is annually surveyed to monitor how effective the previous treatments have been, and any Weed Orchid plants located will be dug out. However the infestation of the African Weed Orchid is known to take up to seven years to eradicate and so we must continue to persevere.

But wait, there’s more, you can help us too. Your actions this spring can help to protect the Marengo Nature Conservation Reserve from the threat of the African Weed Orchid. If you live near the airfield look for the African Weed Orchid in your own garden and street as well as during your walks in the Reserve. If you find a Weed Orchid plant dig it out making sure you dig out all the tubers and roots. If the plant is flowering place the entire plant into a plastic bag before digging roots out (to capture seeds) and seal the bag. Then place the bag of African Weed Orchid in sun for 4 weeks to solarise the seeds before disposing in the rubbish bin. If you find a plant on either your private land or on public land please contact us at the Southern Otway Landcare Network so we can record it and take necessary action (5237 6904 or Avoid walking or moving animals or equipment over the Apollo Bay Airfield infestation during spring to prevent spreading the tiny seeds of the African Weed Orchid. Every little action helps.


Timing - emerges in September/October.

Flowering - throughout October and into November
(around the same time as the native "Purple Flags").

Flowers - displays multiple small, pink, white and yellow flowers.

Height - up to 30cm tall.

Form - has a distinctive thick fleshy stem.


Take it that step further:
Combatting the African Weed Orchid Webinar
Presented by Dr Robin Adair from Australis Biological

Find out more about Marengo’s African weed infestation and how you can help stop the spread with an exclusive FREE Webinar presented by Dr Robin Adair from Australis Biological followed by a Q&A.

Date: 1pm 1st September 2020

Email for Zoom link.


Project funded by Victoria and Department of Environment, Land, Water and Planning Through their Biodiversity Ground Action Grant Program.