Bryony hunting in the Mokai Valley

Department of Conservation —  07/03/2016

By Morgan Couch

Each year, in late October, six students from around the country are chosen by DOC to combat the biosecurity risk known as white bryony. Bryony (Bryonia diocia) was discovered in Mokai Valley in 1991, and since 1999 DOC has been actively working towards its eradication. We are currently working in partnership with MPI on the project.

White bryony summer eradication team rafting on the Rangitikei River.

The white bryony summer eradication team

The weed is a climbing vine, which grows from seedlings up to 6 meters, and grows small white flowers. The females show berries that turn red and are dispersed by birds. The vine can smother tree plants with curled tendrils and shade smaller plants. It is also slightly toxic to animals. Our job is to locate the plants and dig up the underground tubers, which we cut and paste with poison.

The vines shoot out in the spring and die back in the winter, therefore the eradication team is largely made up of university students such as myself seeking summer work and conservation experience. The Rangitikei River is an absolute gem to work on; we had the opportunity to work where few people get to see, with spectacular views daily.

A view of the Rangitikei River.

Spectacular views

A lot of our work consists of grid searching the bush land on either side of the river, along the cliff lines and through the surrounding paddocks for the dreaded bryony. The entire group’s fitness and bush-bashing abilities have significantly improved over the summer.

A white bryony weed.

Target acquired

Later in the season, to get to the remote areas on the riverbanks of the Rangitikei, the team is flown in by helicopter to search. The helicopter also flies in a raft, which we use to travel down the river from each destination to the next.

The team getting helicoptered to sites.

Getting helicoptered to sites

Working for DOC in the remote outdoors is so unlike any other summer job I had ever experienced. It was hard physical work at times, but it was also exciting, and most importantly rewarding in the endeavor to eradicate the plant entirely from the area. In fact, I may have to return next summer.

War on Weeds

Hundreds of invasive weeds are smothering our native forests, wetlands and coastal areas, harming our wildlife and transforming our natural landscapes. We invite you to join with DOC and Weedbusters to fight this war on weeds.

2 responses to Bryony hunting in the Mokai Valley


    Very insightful, love your work


    Great work and what a fantastic student summer job.