Myrtle rust

Myrtle rust is a plant disease caused by the fungus Austropuccinia psidii. It produces powder-like spores that spread through direct contact or by the wind. Once established on a host tree or shrub, it destroys new growth and soft tissue, eventually killing the plant.

Aotearoa has 37 native myrtles, some of which are not found anywhere else in the world. Common examples include:

• pōhutukawa
• rātā
• mānuka
• kānuka.

Many non-native species that are widely distributed across Aotearoa are also susceptible to myrtle rust, including:

• eucalypts
• feijoa
• bottlebrushes
• lilly pilly/monkey apple

Myrtle rust is a serious threat to our biodiversity. Because it is a recent arrival in Aotearoa, it is hard to predict how damaging it will be. Citizen science, where the public involved in monitoring and analysis, is essential to us knowing how myrtle rust spreads and what impact it has.

You can help stop the spread by:

• becoming knowledgeable about which plants are susceptible
• reporting infections on the iNaturalist website or report suspected cases using the contact us form
• not using lilly pilly (monkey apple, Syzygium smithii) as a hedging plant, because it is very susceptible to myrtle rust.