Myrtle Rust
Myrtle rust is a serious fungal disease that affects plants in the Myrtaceae family, such
as rose apple (lilly pilly), tea tree and bottle brush.
Myrtle rust cannot be eradicated and will continue to spread in Queensland because it
produces large numbers of spores that are easily spread by wind, human activity and
animals.
Which plants are affected?
Myrtle rust is known to affect only myrtaceous plants. To date, it has been found on
more than 60 species of myrtaceous plants, including many plants that are commonly
found in gardens. These plant species include:

lilly pilly

scrub cherry

willow myrtle

rose apple

thready bark myrtle
View the full list of known host plants for myrtle rust
Some hosts are affected more severely than others. As myrtle rust has only recently
been detected in Australia, the long-term effect on plants under Australian conditions
is not yet known.
Some plant species may display symptoms that could be confused with myrtle rust.
Only plants in the family Myrtaceae can become infected with myrtle rust. The
following plants are not myrtaceous and, therefore, do not have myrtle rust even if
they display rust-like symptoms.
Which plants are not affected?
Plants commonly mistaken as being infected with myrtle rust include:

frangipanis

grevilleas

palms

banksias

wattles

orchids
What are the symptoms?
Myrtle rust attacks young, soft, actively-growing leaves, shoot tips and young stems,
as well as fruits and flower parts of susceptible plants.
Early symptoms
The first signs of rust infection are tiny raised spots or pustules.
The few bright yellow spores on this lilly pilly (Syzygium australe) indicate a
mild or early infection of myrtle rust
Later symptoms
After a few days, the pustules erupt into distinctive, fluffy-looking, egg-yolk yellow
spores.
The crinkling leaves and yellow spores on this iron or scented malletwood
(Rhodamnia sessiliflora) plant show a moderate infection of myrtle rust
The crinkling leaves and heavy load of myrtle rust spores on this rose apple
(Syzygium jambos) plant indicate a heavy infection
Left untreated, the disease can cause deformed leaves, heavy defoliation of branches,
dieback, stunted growth and even plant death.
How does myrtle rust spread?
Myrtle rust can spread rapidly because it produces large numbers of small spores that
can be dispersed over long distances by wind.
The disease can also spread through the movement of:

infected or contaminated planting material, nursery stock, plant cuttings,
flowers and germplasm

animals such as bees, birds, bats and possums that have been in contact with
rust spores

contaminated plant waste, timber, wood packaging and dunnage

contaminated equipment and tools used on or around plants (e.g. chainsaws,
secateurs)

contaminated clothing, shoes and other personal effects.
Myrtle rust is likely to infect plants in wet and humid conditions, and rust pustules can
mature to release spores in as little as 10-12 days. Spores can survive for up to three
months in the environment.
5 steps for reducing the spread of myrtle rust
Myrtle rust can be spread on plants and cuttings, on the wind, and through contact
with people and animals. Myrtle rust may naturally spread to your property as the
disease progresses but there are five simple steps you can take to help slow the
spread of myrtle rust.
1. Buy healthy plants
Make sure myrtaceous plants bought for your garden are free from the symptoms of
myrtle rust. Inspect the foliage and stems of myrtaceous plants before you buy them,
and avoid purchasing plants that have signs of disease.
2. Clean equipment
Always clean your gardening tools and gloves with detergent and water after use. This
is especially important if you have used the tools on another property.
3. Clean your clothes
If you have been to a nursery, park, bushland area or another garden, change your
clothes before going into your own garden. Wash these clothes and hats before
wearing them into your garden. This will help avoid the potential transfer of myrtle
rust spores from your clothes onto your plants.
4. Inspect regularly
Regularly inspect myrtaceous plants in your garden for signs of myrtle rust. Early
detection in your garden will give you time to consider options for myrtle rust control
on your property.
5. Monitor your plants
If myrtle rust does establish on your property, monitor your plants regularly. Note
which plants become the most severely affected and consider not replanting with
these types of plants.
What should I do if I find myrtle rust on my property?
Do not take plants you think may be infected with myrtle rust to your
nursery as this may spread spores.
If you suspect that you have seen myrtle rust, ring Biosecurity Queensland on 13 25
23 or fill in the online form. When you report a suspected new detection of myrtle
rust, Biosecurity Queensland can help you identify the disease, and give you
information about the disease and its management.
Reporting the disease gives Biosecurity Queensland information about the diseases
geographic distribution, host range and impacts. They use this information to give the
nursery industry and businesses up-to-date information about the impacts of myrtle
rust and management of the disease.
Do not move any plants that you think may be infected with myrtle rust off your
property, as this could spread the disease
Treating myrtle rust on your property
Myrtle rust cannot be eradicated and will continue to spread in Queensland, as it
produces large numbers of spores that are easily spread by wind, human activity and
animals.
If you have myrtle rust-infected plants on your property, or are at risk of getting
myrtle rust on your property, there are several strategies you can implement to limit
the spread of the disease.
Treating plants infected by myrtle rust
If myrtle rust becomes established on your property, there are several strategies you
can use to limit the spread of the disease and help protect your garden plants. The
strategy you select should be appropriate to your specific situation. This can include:

spraying with fungicide

removing and disposing of diseased plants

removing and disposing of healthy plants as a preventative measure.
You could combine one or more of these strategies to effectively control myrtle rust
on your property.
Spraying with fungicide
The Australian Pesticides and Veterinary Medicines Authority (APVMA) has issued the
following permits for certain fungicides to be used to control myrtle rust on plants and
plant-related materials:

For the control of myrtle rust in ornamentals and non-fruit bearing plants of
the myrtaceae family in home gardens (PER12828) (PDF, 28 kB)

For the treatment of nursery stock (non-food), ornamentals, non-bearing fruit
trees and cut flowers/foliage for myrtle rust (PER12156) (PDF, 52 kB)

For the decontamination of vehicles, tools and equipment that has come into
contact with myrtle rust infected material (PER10535) (PDF 18 kB)
Visit the APVMA website for more information about these permits.
Before using the fungicides, read the permit in conjunction with the product label to
determine the relevant directions for use, rate of application and critical use
instructions that may apply.
When you use fungicides, it is important to rotate them to maintain their usefulness.
Contact your local nursery, garden centre or agricultural chemical supplier for
information on the range of chemicals that are suitable for use in any individual
situation.
Removing and disposing of diseased plants
Removal
To minimise the potential spread of spores, spray infected plants with an approved
fungicide the day before you intend to remove the plant. If it is not possible to treat
with a fungicide, carefully wet the plant foliage to dampen any spores that are likely
to be dispersed during the removal process.
The method of plant removal will depend on the size and number of plants:

small plants can be enclosed in a plastic bag to reduce spore dispersal before
being pulled or dug out of the ground. For potted plants, the whole plant,
including the pot, should be placed into the bag and sealed

large plants can be cut into smaller pieces, wrapped in black plastic and placed
in the sun for 3-4 weeks (a process called solarisation). Alternatively, plant
parts can be placed in plastic bags and sealed for offsite disposal.
Disposal
Dispose of infected plants (or plant parts) by implementing any of these options:

burying on-site

placing in general domestic waste bins (only when enclosed in plastic bags) or
transporting in a covered vehicle/trailer to a council general waste disposal
site (not green waste)

securely covering and sealing the entire plant within black plastic (or similar)
and placing in direct sunlight for 3-4 weeks (a process called solarisation).
We do not recommend that you use infected plants as mulch, as this distributes
infected plant material and may spread myrtle rust.
Removing and disposing of healthy plants as a preventative
measure
Some species of plants are known to be highly susceptible to and severely affected by
myrtle rust. You can remove these species prior to infection to reduce the risk of a
significant infection developing on your property.
You can dispose of healthy plants that show no signs of myrtle rust infection as
normal garden waste. If you are unsure whether plants are infected with myrtle rust,
dispose of them using the methods outlined for removing diseased plants.
Replanting
If you have removed infected myrtaceous plants, replanting with similar species may
cause the disease to re-occur. Select replacement plants that are unlikely to become
infected. Contact your local nursery for advice on other suitable plant types for your
garden.
Take time to observe what is happening in your garden to determine which plants are
less susceptible to the disease. This can help guide your future planting choices.
Hygiene
After removing and disposing of infected plants, wash clothing and clean any
equipment with water and detergent or a registered chemical before starting other
activities that may infect further plants.
You can reuse pots, wooden stakes and other items that have been in contact with an
infected plant. However, you should thoroughly scrub these items with detergent and
water, and leave them to dry completely, before reusing them.
Implementing good hygiene and decontamination practices will also aid in the control
of myrtle rust.
Reporting
If you suspect that myrtle rust may be in other locations off your property, notify
Biosecurity Queensland on 13 25 23 or by filling out the online reporting form.
© The State of Queensland (Department of Agriculture, Fisheries and Forestry) 1995 – 2012
Queensland Government