Myrtle Rust – a gardener’s guide

You may be aware that there is a new plant disease called Myrtle Rust invading our region.

Myrtle Rust is a fungal disease which attacks members of the Myrtle family, ie natives such as eucalypts, tea-trees, lilly-pillies, melaleucas, and exotics (non-natives) such as the Rose Apple (Syzygium jambos). We’ll get to the bad news shortly, but the good news is, Myrtle Rust only attacks myrtle plants and it will not infect your banksias, grevilleas, wattles, gardenias, graptophyllums or any other natives. The other good news is that experience from ‘down south’ (where the disease has been established for some time) shows that, while some myrtle plants are severely affected, a large number of myrtle species appear to be only moderately susceptible or even relatively tolerant. So you can still have a beautiful native garden.

However, Myrtle Rust is not a disease to dismiss lightly. It is a serious disease, and it may eventually kill the plant. It attacks the new growth, where it first appears as red/purple/brown blotches disfiguring the leaves. But after a short time it bursts into spores, which are released as a bright golden powder. Infected plants have been described as having so many spores that they are literally glowing bright yellow.

The powdery spores of Myrtle Rust are spread very easily, by just about every method you can think of, including wind and water (rain and irrigation), animals (birds, insects, possums etc), and human activity. There’s not a lot you can do about wind, animals, birds and insects, but people are also major carriers of the disease, by buying or swapping infected plants, and carrying it on their clothes and vehicles. This is undoubtedly how the disease spread to our region in the first place.

So the most important thing is to take steps not to spread it. Here’s a few hints:

  1. Please DO NOT bring a sample to Yuruga for identification (or take samples anywhere for that matter). A photo on your digital camera will be perfectly adequate.
  2. DO destroy the infected material (or better still, the whole plant) by placing the plant material in a plastic bag, sealing the bag securely, and placing the sealed bag in your rubbish bin. DO NOT dispose of infected material in green waste.
  3. DO thoroughly clean everything that has come into contact with the infected plant by washing the secateurs in metho, washing your clothes (including your hat and shoes), and showering yourself (including washing your hair).
  4. DO be very careful where you get plants from. DO buy plants only from accredited nurseries which have a Myrtle Rust management plan in place. These plants will be clean and free of the disease. DO NOT buy or swap plants if you cannot be sure they are clean.

Yes, Yuruga certainly does have an active Myrtle Rust Management Plan in place.

So, see you at Yuruga, and happy (Myrtle Rust free) gardening!
Peter and Ann

And for loads more information, go to the Biosecurity Queensland website