Lilly Pilly Problems/Diseases: Identification & Treatment Advice

Written By:
Scott Carroll
Published On:
July 17, 2023
Lilly Pilly Fruit

Lilly Pilly is the simple plant name for the Syzygium family of plants. The Syzygium Australe variety of plants, commonly known in the landscape industry as Brush Cherry or Scrub Cherry, is a well-known native plant of Australia. 

Our continent is home to more than 60 types of Lilly Pilly. They range in size from shrubs to small trees and everything in between. These plants are beautiful and ornate in their foliage and are fairly fast-growing.

Lily Pilly at a Glance

Lilly Pilly plants are generally seen as non-invasive. As native plants, they are preferred for use in landscapes, especially those with limited space and those needing minimal fertiliser or specialised care. 

In a general summary of the plant:

  • Height: 1–10m+, easily pruned to desired size and shape
  • Foliage: Shiny and smooth. New foliage is often colourful, with older foliage being shades of green. This leads to multi-coloured and stunning specimens. The hearty nature makes Lilly Pilly diseases a rare issue compared to other plants.
  • Use: Commonly grown as a hedge or windbreak, as a simple tree or shrub, and as ornamental focal point specimens.
  • Climate: Does well in all regions that are not arid or too cold; protection from occasional temperature drops is necessary.
  • Soil: Thrives best in deep, organically rich soil, but adaptable. Smaller specimens can grow well in pots and containers.
  • Position: Mostly sunny to partial shade.
  • Flowering and fruiting: Simple yet showy “powder puff” flowers appear from spring through autumn. After flowering, the colourful and usually edible fruit appears.
  • Feeding: Use a quality controlled-release fertiliser during the active growing season.
  • Watering: Plants should be mulched and need to be in moisture-retaining yet well-drained soil.

What is the average lifespan of a Lilly Pilly?

The average life expectancy for a healthy specimen is around 20 years, depending on the growing conditions and how well it has been cared for. The Lilly Pilly plant in general will begin producing fruits from the first year of full mature growth. Fruits start pale but are ready to harvest in the winter when they turn red or pink. A healthy plant will grow and produce fruits until it dies.

5 common Lilly Pilly problems

Although Lilly Pillies are hardy plants that can often thrive in Australia’s unpredictable weather, they are particularly susceptible to some pest and disease issues. Such common problems in:

  1. Phytophthora disease
  2. Root rot
  3. Myrtle rust
  4. White scale
  5. Pests

Below, we’ll talk you through some of these common problems so you can best be prepared to deal with them if they arise in your Lilly Pilly!

1. Phytophthora disease

  • Signs: Wilting foliage, changes in leaf colour, dark patches on the trunk, an overall decline in plant health.
  • Treatment options: Improve soil conditions, provide good drainage, avoid overwatering the plant.

The fungi, known as Phytophthora, cause root rot, attacking the roots and weakening the entire plant. Early signs of this condition are yellowing leaves and wilted or droopy stems. When seeing the wilted state, many people mistakenly think that a lack of water is the issue and complicate the problem by watering the plant even more.

2. Root rot

  • Signs: Oedema, Yellowing and wilting leaves, stunted growth, lack of vigour or feeding response.
  • Treatment options: Improve soil drainage, water properly, and maintain healthy conditions.

While some rot is caused by fungi contaminating the soil, other Lilly Pilly diseases are caused by poor watering and soil conditions. General root rot is usually the result of poor drainage, overwatering, or seasonal deludes of rainfall. The first and most obvious sign of root rot is the overall decline in plant health.

3. Myrtle rust

  • Signs: Rusty flecks, distorted growth, yellow and brown leaves, branch tip dieback.
  • Treatment options: Maintain proper trimming and pruning, applying fungicides, and good plant hygiene.

Most growers who used Lilly Pilly plants will encounter Myrtle Rust at some point and time. It appears as rust-coloured fungal spots and specks, usually occurring on the new tender growth. The leaves infected with Myrtle Rust get yellow spots that grow and then spread before the leaf goes brown. The disease will spread and can infect other plants as well.

4. White scale

  • Signs: Wilted and deformed leaves, decrease in plant vigour, and poor overall growth.
  • Treatment options: Spraying with pet control products, removing damaged or infected stems.

White scale often attacks Lilly Pillies and is another common pest. This white waxy coat can be seen on the stems and leaves. In plants affected by white scale, there may also be black mould on the plant and ant infestations. The black mould is caused by honeydew that is made by the scale and attracts ants to the plant.

5. Pests 

  • Signs: Pinprick holes in leaves, discolouration of leaves, warping and deformity of the plant.
  • Treatment options: Pesticides, safe soaps, removal of infected leaves and branches.

Anyone growing or using Lilly Pilly plants needs to know to look out for insects known as psyllid (Trioza egeniae). Many varieties of Lilly Pilly plants are prone to infestations from these voracious pests. These pests suck sap from the new leaves, which leaves the plant with deformed and damaged leaves that don’t grow properly and die off.

How do you overcome Lilly Pilly Problems?

Most Lilly Pilly varieties need high moisture levels and require frequent watering during the dry months. The smartest way to keep the soil moist without saturating the roots or wasting water with daily soakings is with a drip irrigation system. By attaching a timer, you can program automatic watering to the soil and adjust volume and timing as the seasons change.

You should also consider using fertiliser on your Lilly Pilly at least annually in the growing season. The best option is a slow-release fertiliser that will feed for at least 4-6 months. There is no need to use an expensive fertiliser as a basic flower, and shrub formulation will work fine. Adding organic matter to the soil can also boost nutrient access and improve moisture.

How do you keep Lilly Pilly healthy?

Sometimes the fruiting nature of the Lilly Pilly can be an inconvenience. Along sidewalks, near decks, patios, or around pools, the falling fruit can be a real headache for homeowners. This can be avoided simply by cutting off the dead flower heads, preventing fruit development. It takes a little more effort but saves time on messy cleanups.

If you’d like to learn more about keeping a healthy hedge, read up on how to keep a Lilly Pilly thick and flourishing.

Final thoughts

With stunning foliage, rapid growth, and versatile uses, there is no doubt Lilly Pilly is a favourite in gardens and landscapes across the continent. Despite the hearty nature of the plan, Lilly Pilly does suffer from some issues, such as fungal rot, Myrtle Rust, and psyllid insects. 

Early detection of these and other similar issues, such as overwater or poor drainage concerns, must be addressed early on. Taking care of Lilly Pilly plants is easy so long as the basic criteria for a healthy plant are maintained and homeowners know what pests and diseases to be on the lookout for. Dealing with Lilly Pilly problems shouldn’t make it impossible to enjoy these stunning plants.


Can lilly pilly be cut back?

Lilly Pilly is commonly used as a hedge or screen plant. They can be pruned back into any shape or size that is needed. It is advisable to use smaller varieties if you are looking for a smaller hedge or windbreak.

Do Lilly Pilly plants need a lot of water?

These plants need moist and well-drained soil, and while they can tolerate a few days of dry conditions, they will not thrive long-term without good watering practices.

Is neem oil good for lilly pilly?

Neem oil and similar products can be used on Lilly Pilly so long as the instructions are followed closely. It is a good idea to avoid using these products in the heat of the day in order to reduce the risk of the oil burning the leaves in the sun.