Weed Infestation Cut Short

Yellow Flag Iris found here for the first time.

An infestation of the pest plant Yellow Flag Iris has been found by Waikato RiverCare staff in an oxbow wetland on the Mangawara Stream. This is the first confirmed find for Yellow Flag Iris in the Mangawara catchment and is particularly concerning given its location upstream of the main infestation on the lower Waikato River. Yellow Flag Iris is a very undesirable weed due to it forming dense stands that can displace native species and restrict access for recreational activities.

However, thanks to the vigilance of Kevin Hutchinson, Waikato RiverCare’s operations manager, this

infestation has been identified and eliminated before seeding.

Yellow Flag Iris, a native of Europe, Asia and North Africa, was introduced into New Zealand as an ornamental plant, but it has since spread to other sites around the country, particularly along the banks of the lower Waikato River.

Early detection and immediate control is vital in stopping the spread of this weed. The seed pods of this particular infestation were trimmed to prevent the spread. Continued observation of the oxbow will ensure Yellow Flag Iris has been eradicated from the Mangawara catchment.

For more information on yellow flag iris, please refer to Waikato Regional Council’s website.