How to recognise myrtle rust
Keep an eye out for myrtle rust in your garden, local parks, and other green areas. Recognise symptoms so you can help protect our environment.
Plants to check for myrtle rust
Myrtle rust is a serious fungal disease that affects plants in the myrtle family. Some of our most iconic native plants are vulnerable to myrtle rust, including:
- pōhutukawa
- mānuka
- rātā
- swamp maire
- ramarama.
Some exotic species can also get the disease, including ornamental plants like bottlebrush and lilly pily.
List of species found with myrtle rust in NZ
Symptoms to look for
Look out for symptoms of myrtle rust, including:
- bright yellow powdery eruptions appearing on the underside of the leaf (young infection)
- bright yellow powdery eruptions on both sides of the leaf (mature infection)
- grey, 'fuzzy' spore growth on undersides of leaves
- some leaves may become buckled or twisted and die off.
Use the images below to help identify myrtle rust
Pōhutukawa with single myrtle rust pustule
Pōhutukawa is a New Zealand endemic species with a natural distribution in the upper half of the North Island, mainly in coastal areas. It is a coloniser of bare coastal rock and is an important species for coastal stability.
Pōhutukawa with myrtle rust dieback
Pōhutukawa, Metrosideros excelsa with leaves covered in myrtle rust pustules, causing dieback.
Lemon myrtle leave with myrtle rust
Lemon myrtle, Backhousia citriodora is a non-native myrtle which has been cultivated and grown in home gardens. It is an evergreen shrub growing to a height of 6 m and prefers warm tropical conditions.
Maire tawake with myrtle rust on flower buds
Maire tawake or commonly known as swamp maire Syzygium maire is the only endemic Syzygium species in New Zealand.
Myrtle rust yellow pustules on flower buds, flowering occurs during the summer months. Maire tawake can be found in waterlogged areas across the North Island and the top of the South Island, only small remnant populations remain due to extensive habitat loss.
Rōhutu with myrtle rust on flower bud
Rōhutu, Lophomyrtus obcordata with myrtle rust pustules on leaves, stem and flower buds. Distribution it patchy across the North and South Island’s of New Zealand. Rōhutu naturally hybridise with ramarama; hybrids are fully fertile and susceptible to myrtle rust.
Ramarama flower myrtle rust
Myrtle rust yellow pustules on the flower calyx of ramarama lophomyrtus bullata flowers. Flowering occurs in the summer months.
Ramarama flower bud with myrtle rust
Yellow myrtle rust pustules on the calyx of the flower bud, flowering occurs over the summer months with fruit maturing in autumn.
Pōhutukawa with myrtle rust
Close up of myrtle rust infection on Kermadec Pōhutukawa. Pōhutukawa is New Zealand's Christmas tree, and holds a prominent place in Maori mythology. Although the fortunes of pōhutukawa and rata have changed for the better, they are still threatened by people and pests. Photo credit DOC.
Rātā with myrtle rust
Rātā with brown lesions and yellow spores indicating myrtle rust. Rātā trees, along with the pōhutukawa, are one of the best known native trees in New Zealand. Native birds benefit from rātā, but as possum numbers increase the threat to native birds and to rātā has also grown.
Pōhutukawa with myrtle rust
Pōhutukawa with yellow spores on new stem growth indicating myrtle rust. Pōhutukawa is New Zealand's Christmas tree, and holds a prominent place in Maori mythology. Although the fortunes of pōhutukawa and rata have changed for the better, they are still threatened by people and pests. Photo credit DOC.
