Plants Threats

Introduced plants, plant pests and plant diseases pose a serious and on-going threat to New Zealand's native plants and trees, as well as our agricultural and horticultural crops and plantation forests.

This section deals with some high profile plant threats – the Pest and Diseases List will give you a list of plant pests and diseases that the public may be expected to come across.

Plant threats can be grouped into three areas:

  • Plants that are pests in themselves
  • Pests that threaten plants
  • Diseases that threaten plants

There are strict controls on bringing plant material (offsite link to into New Zealand and there are detailed lists of unwanted plants and those plants targeted for action.

Members of the public have an important role to play by keeping watch for anything potentially exotic or unwanted. If you suspect you have seen or found an unwanted pest or disease please call the Biosecurity New Zealand hotline on 0800 80 99 66. For information on pests and contaminants found on or in containers (air or sea) please refer to the See Contain Report brochure Link to PDF document (2941 KB) and poster Link to PDF document (2227 KB).

If you see plant disease symptoms and you are unsure whether or not they are caused by a new disease, a sample may be sent to MPI’s Plant Health & Environment Laboratory. Diagnosis of submissions of suspect new plant diseases from the general public, regional councils, crop consultants and the scientific community is provided free. The lab does not provide testing for local diseases that are established in New Zealand.

  • Submission form Link to PDF document (199 KB), including instructions for sending samples to the laboratory

Samples should be sent to:
FREEPOST 120201, Plant Health & Environment Lab, IDC-Tamaki, 231 Morrin Road, St Johns, PO Box 2095, Auckland 1140, New Zealand
Tel: 09 909 3015, Fax: 09 909 5739

Plants that are Pests

There are a number of established pest plants which are top priority nationwide and are part of the National Interest Pest Response programme

A large number of introduced plants threaten New Zealand's land or aquatic environment. The National Pest Plant Accord signed with the nursery industry identifies the list of exotic plants that cannot be sold or propagated.

There are a number of pest plants that cause significant environmental damage that are not wanted in New Zealand. This list includes some species known to be ranked in the top 100 of the worlds worst invasive alien species (offsite link to

High profile campaigns are also underway against:

Weedbusters is an independent awareness and education programme that aims to work with all agencies involved in work to protect New Zealand’s environment from the threat of weeds.

Visit the Weedbusters website for information on weed species, resources and information on how to take action in your community to reduce the impact of weeds on the environment, economy and human health.

Pests that threaten Plants

Pests can also prove a major threat to native plants and imported crops or forests.

Among the high profile plant pests currently targeted are:

Diseases that threaten Plants

Diseases – fungi, bacteria and viruses that spread among plants - can have a devastating impact on horticultural or forestry sectors as well as our conservation estate.

Page last updated: 26 May 2015