Most Common Lawn Diseases in Australia

diseased lawn is patchy

At Joondalup Turf Farm, we understand the pride and joy that comes with maintaining a lush, vibrant lawn. However, just like any living organism, your lawn can fall victim to pesky diseases that threaten its health and beauty. But fear not! Armed with knowledge and a proactive approach, you can keep your turf thriving all year round. Let’s dive into understanding, identifying, and treating common lawn diseases. 

Understanding Common Lawn Diseases 

Lawn diseases can be caused by various factors including fungi, bacteria, and environmental stressors. These diseases often manifest in the form of discoloured patches, wilted grass, and unusual growth patterns. Some of the most prevalent lawn diseases include fungal infections like brown patch, dollar spot, red thread, and powdery mildew. 

Identifying Symptoms of Lawn Disease 

Being able to recognise the early signs of lawn disease is crucial for effective treatment. Keep an eye out for symptoms such as yellow or brown patches, thinning grass, mould or mildew growth, and unusual spots or lesions on the blades. By promptly identifying these symptoms, you can take proactive measures to prevent further spread. 

Common Occurring Lawn Diseases  


More likely to strike during warm, humid conditions. Infected areas are reddish/brown turning to yellow and light browns, most often in patches. This can be treated with Mancozeb fungicide. 

2. Powdery Mildew 

A disease caused by fungus, leaving grass blades covered in a white powder. This is due  to multiple factors, including poor circulation, too much shade and high humidity. Luckily, it does not spread easily, and can be treated with fungicide.  

3. Fusarium Patch  

Warm/brown patches appear in the lawn occurring in warm and wet conditions. Remove thatch and use a balanced, high nitrogen fertiliser, avoiding late afternoon/evening watering. 

4. Brown Patch Lawn Disease 

A fungal disease found in warm/wet conditions which produces brown circular patches ranging in size from centimetres to a few metres in diameter. Avoid evening watering, treating with moderate amounts of fertiliser and Mancozeb fungicide.  

5. Dollar Spot  

A disease more prevalent in southern parts of Australia during periods of high humidity. Small, dollar sized spots appear dark at first, then turning brown, light brown to almost white. Remove thatch layer and use a high nitrogen fertiliser, treating with Mancozeb fungicide.  

6. Red Thread  

Most often affecting cool season grasses, first signs include small yellow to brown patches with small red threads or needles. This disease spreads to cover large areas and is most common in low nitrogen lawns. Treat with a nitrogen-based fungicide that is specifically for red thread use, followed by a nitrogen-based fertiliser.  

Preventative Measures for Lawn Disease Treatment 

Preventative measures are the first line of defence in safeguarding your lawn against the onslaught of diseases. Start by implementing good lawn care practices, such as regular mowing to maintain optimal grass height and improve air circulation. Proper watering is crucial; aim for deep, infrequent watering sessions in the morning to discourage fungal growth. Adequate fertilisation with a balanced blend of nutrients strengthens your turf’s defences, so choose fertilisers wisely, avoiding excessive nitrogen in favour of balanced formulations. 

Remember to aerate your lawn periodically to reduce thatch buildup and promote healthy root growth. Lastly, select disease-resistant grass varieties suited to your region’s climate and environmental conditions, minimising the risk of infection. By proactively implementing these preventative measures, you’ll create an inhospitable environment for lawn diseases, ensuring your turf remains resilient and vibrant year-round. 

Effective Options for Lawn Disease Treatment 

Effective treatment options for common lawn diseases vary depending on the specific type of infection. Fungal diseases often respond well to fungicides, such as Mancozeb or neem oil, which can help halt the spread of the infection and promote recovery. Bacterial diseases may require bactericides for effective control. Additionally, cultural practices like improving drainage, reducing thatch buildup, and adjusting watering and fertilisation schedules can aid in disease management. Organic treatments, such as compost tea or beneficial microbes, can also be effective in restoring balance to the soil ecosystem and suppressing disease development. It’s essential to carefully follow the instructions provided with any treatment product and to consult with a lawn care professional for guidance on the most appropriate course of action for your specific situation. By combining targeted treatments with proactive lawn care practices, you can effectively combat common lawn diseases and restore your turf to its healthy, vibrant state. 

How to Treat Lawn Disease 

Maintaining a disease-free lawn requires ongoing diligence and care. Regular monitoring is essential; keep a keen eye out for any signs of disease, such as discolouration, thinning grass, or unusual growth patterns. Promptly address any issues that arise by implementing targeted treatments and adjustments to your lawn care routine.  

Ensure your lawn receives proper nutrition by fertilising according to the specific needs of your grass type and local conditions. Keep your lawn well-groomed by mowing at the appropriate height and aerating periodically to promote airflow and reduce thatch buildup. Minimise stressors on your lawn, such as excessive foot traffic or compaction, and avoid overuse of chemicals that can disrupt the natural balance of your turf ecosystem. By maintaining a vigilant and proactive approach to lawn care, you can create an environment that is inhospitable to disease, allowing your lawn to thrive and flourish for years to come.