Battling Disease: Fight Common Winter Lawn Diseases

Battling Disease: Fight Common Winter Lawn Diseases

For many Australians, our lawns are not just plots of land - they represent our deep-rooted affinity for the great outdoors. They serve as tranquil retreats, spaces where we can connect with the natural world in our very own backyard. A verdant, well-tended lawn doesn't merely beautify our homes; it significantly contributes to our overall well-being and bolsters the biodiversity of our local ecosystems. However, the advent of winter often sees our cherished patches of green besieged by an array of lawn diseases, undermining their vitality and vigour.

To help your garden navigate the chills of winter and emerge healthy and lush, we've compiled a comprehensive guide. Delving into the prevalent winter lawn diseases across the northern and southern regions of Australia, this resource furnishes you with detailed insights and equips you with practical, effective strategies to combat these challenges. With this guide, your lawn can continue to thrive, remain resilient and maintain its captivating charm, irrespective of the season.

The Australian Climate: An Understanding of the Northern and Southern Regions

Australia's geographical diversity creates a stark climatic contrast between its northern and southern regions. The tropical north differs significantly from the temperate south, a variation that largely influences the kind of lawn diseases that homeowners might encounter. A clear understanding of these specific climatic conditions is the first step in formulating effective strategies for preventing and treating lawn diseases.

Proactive Strategies to Combat Common Winter Lawn Diseases in Northern Australia

Home to a tropical climate, Northern Australia witnesses an upsurge of lawn diseases during the winter months, including Dollar Spot, Anthracnose, Brown Patch, Fairy Ring, and Spring Dead Spot. The unique climatic conditions of Northern Australia necessitate specific strategies to combat these common diseases. Here's how to tackle each disease effectively:

  • Dollar Spot:

    Dollar Spot, identifiable by small straw-coloured spots roughly the size of a dollar coin, is a consequence of the fungus Sclerotinia homoeocarpa. This fungus prospers in humid conditions, making the tropical climate of Northern Australia an ideal environment for its proliferation.

    How to combat Dollar Spot

    Balanced Fertilisation: Regularly applying balanced fertiliser is paramount to maintaining a healthy lawn. Nitrogen-deficient lawns are particularly susceptible to Dollar Spot, so a fertiliser with sufficient nitrogen content is essential.
    Proper Irrigation: Water your lawn in the morning to allow the grass to dry during the day, thereby reducing moisture levels that encourage fungus growth.
    Effective Fungicides: Fungicides like Tombstone Duo or with active ingredients like propiconazole can be helpful for severe infections. Always follow the product's label instructions for optimal results.

  • Anthracnose:

    Anthracnose is characterised by irregular, yellow patches that can inflict significant damage if left unchecked. Caused by the Colletotrichum species, this disease thrives in warm, wet conditions typical of Northern Australia.

    Treating Anthracnose

    Disease-Resistant Varieties: Planting grass varieties resistant to Anthracnose can be a helpful preventive measure.
    Recommended Mowing Practices: Ensure your grass is maintained at the recommended height for its variety. Longer grass tends to be less prone to Anthracnose.
    Fungicide Use: Consider fungicides like Tombstone Duo, or with active ingredients like azoxystrobin or chlorothalonil for treating Anthracnose. Remember to alternate between different fungicide classes to prevent the fungus from developing resistance.

  • Brown Patch:

    Caused by the Rhizoctonia species, Brown Patch results in large circular patches of light brown grass. The fungus flourishes in warm, damp conditions common in Northern Australia's tropical climate.

    Combatting Brown Patch

    Efficient Irrigation: Overwatering your lawn can encourage the growth of Brown Patch. Maintain a balance to prevent this.
    Regular Aeration: Regular aeration can significantly improve soil drainage and prevent conditions favourable for Brown Patch.
    Fungicides: Consider using fungicides like Tombstone Duo, or containing azoxystrobin for treating Brown Patch. Rotate fungicides to prevent the development of resistance.

  • Fairy Ring:

    Named for the mythical creatures purported to cause the circular growth, Fairy Ring is a lawn disease caused by a group of fungi that produce visually distinct rings in the grass. These rings often manifest as lush green patches, but in severe cases, they can result in necrotic or dead patches.

    Treating Fairy Ring

    Balanced Fertilisation: Regular and balanced fertilisation can mitigate the visible effects of Fairy Ring.
    Aeration and Watering: Regular aeration, combined with deep watering, can help move nutrients into the root zone and decrease the visual symptoms of this disease.
    Fungicides: consider using fungicides like Monstar SC which is registered to treat fair ring. Some other fungicides may suppress Fairy Ring symptoms, but they must be applied before symptoms appear.

  • Spring Dead Spot:

    Despite its name, Spring Dead Spot becomes evident when Bermuda grass emerges from winter dormancy. It's caused by the fungus Ophiosphaerella Korra, which can significantly damage overseeded lawns.

    How to treat Spring Dead Spot

    Resistant Varieties: Consider planting varieties of Bermuda grass that are resistant to Spring Dead Spot.
    Proper Fertilisation: Avoid excessive nitrogen in the autumn months.
    Fungicides: Apply fungicides like Adama Bumper or Syngenta Heritage Maxx - both registered to treat Spring Dead Spot.

  • Helminthosporium (Helmo):

    Also known as Helmo, Helminthosporium leaf spot, caused by Bipolaris spp., is prevalent in the northern parts of Australia, particularly during cooler seasons. It manifests as small brown or purple oval spots on leaf blades, and in severe cases, it may cause complete yellowing and death of the leaf.

    Combating Helmo

    Balanced Fertilisation: Avoid over-fertilisation, especially with high nitrogen levels, which can exacerbate Helmo. A balanced slow-release fertiliser applied appropriately can help prevent and control this disease.
    Proper Irrigation: Water your lawn deeply but infrequently, preferably in the morning, to reduce the moisture content and thereby limit the spread of the fungus.
    Fungicides: Fungicides like Tombstone Duo, or containing propiconazole or mancozeb can be useful in treating Helmo. Always use the product as per the label instructions.

  • Grey Leaf Spot:

    Grey Leaf Spot is a lawn disease caused by the fungus Pyricularia grisea. It is characterised by grey or tan leaf spots with darker borders. If left untreated, it can cause extensive damage, including significant thinning of your lawn.

    How to treat Grey Leaf Spot

    Disease-Resistant Varieties: Opt for grass varieties resistant to Grey Leaf Spot, such as certain cultivars of couch or buffalo grass.
    Proper Mowing: Mow your lawn regularly but avoid cutting it too short, as this can stress the grass and make it more susceptible to Grey Leaf Spot.
    Fungicides: Fungicides like Syngenta Heritage Maxx or others containing active ingredients like propiconazole or azoxystrobin can be effective against Grey Leaf Spot. Remember to follow the label instructions for optimal results.

Effectively Combatting Common Winter Lawn Diseases in Southern Australia

The temperate climate of southern Australia gives rise to different diseases in winter, including Red Thread, Fusarium Patch, Snow Mould, Leaf Spot, and Rust, requiring a slightly different approach to disease management:

  • Red Thread:

    Red Thread, caused by the fungus Laetisaria fuciformis, presents as pinkish-red threads extending from the grass blade tips. This disease is more common in cool, humid conditions, typical of Southern Australia's winters.

    Treating Red Thread

    Balanced Fertilisation: Ensure regular application of a balanced fertiliser to your lawn, as those with low nitrogen levels are more susceptible to Red Thread.
    Debris Removal: Keep your lawn clear of leaves and other debris to improve air circulation and reduce moisture levels.
    Fungicides: Consider using fungicides like EnviroMax Azoxystrobin 250SC or others containing mancozeb to treat Red Thread effectively. Follow the manufacturer's instructions for use.

  • Fusarium Patch:

    Fusarium Patch manifests as small, brown, circular patches that can enlarge and merge if not promptly treated. This disease results from the fungus Microdochium nivale, which is most active in cool, wet weather.

    Treating Fusarium

    Optimal Watering: Avoid overwatering your lawn. Water deeply but infrequently, preferably in the morning.
    Proper Aeration: Regularly aerate your lawn to improve drainage and prevent conditions that promote Fusarium Patch.
    Fungicides: Fungicides like Tombstone Duo or with active ingredients like fludioxonil may be considered. Always follow the label instructions.

  • Leaf Spot:

    Leaf Spot can manifest in different forms, usually as small, dark spots on leaf blades. It's caused by several types of fungi, including Bipolaris, Drechslera, and Exserohilum.

    Treating Leaf Spot

    Balanced Fertilisation: Over-fertilisation, particularly with nitrogen, can exacerbate Leaf Spot. Apply a balanced fertiliser to your lawn.
    Proper Irrigation: Water your lawn early in the day to allow the grass to dry before evening.
    Fungicides: Fungicides like Tombstone Duo, or others containing propiconazole may help control Leaf Spot.

  • Rust:

    Rust disease gets its name from the rust-like spores that appear on grass blades. The Puccinia species of fungi most commonly cause it and thrives in conditions with plenty of moisture and low light.

    Treating Rust

    Fertilisation: A well-fertilised lawn can help prevent Rust.
    Regular Mowing: Regular mowing can help remove Rust spores and prevent the disease from spreading.
    Fungicides: Fungicides like Tombstone Duo, or containing azoxystrobin may effectively control Rust. Always apply according to label instructions.

  • Helminthosporium (Helmo):

    Helminthosporium (Helmo) is also a concern in the southern regions of Australia, which witness cooler winters. The temperate climate creates favourable conditions for Helmo to thrive, resulting in significant damage to lawns if left untreated.

    Combating Helmo

    Balanced Fertilisation: Avoid high-nitrogen fertilisers, as they can contribute to Helmo. Instead, use a balanced slow-release fertiliser to nourish your lawn appropriately.
    Irrigation Practices: Try to water your lawn in the early morning, allowing it to dry throughout the day. This practice reduces lingering moisture, which encourages fungal growth.
    Fungicides: Fungicides like Tombstone Duo, or containing propiconazole or mancozeb are typically effective in controlling Helmo. Always use the fungicides in line with the label instructions for best results.

Key Products for Effective Lawn Care in Australia

Investing in quality lawn care products is crucial in preventing and treating lawn diseases. Essential products include fungicides suitable for specific diseases common in your region, lawn aerators to improve soil drainage, and slow-release fertilisers to provide sustained nourishment to your lawn over the winter period.

Follow Instructions!

Adhering strictly to the application instructions and safety data sheet of any lawn care products you utilise is paramount. Remember, these instructions aren't merely advisory but are carefully crafted directives that ensure the product's efficacy whilst safeguarding your well-being and that of the surrounding environment. Such labels and data sheets offer invaluable information, encompassing the appropriate dosages, safe handling procedures, recommended personal protective equipment, and crucial environmental precautions. By following these directives, you can amplify the effectiveness of your lawn care products and uphold necessary safety standards, thus fostering responsible and environmentally-friendly gardening practices. Remember that the label isn't just an afterthought—it's your essential guide to ensuring successful, safe, and sustainable lawn care.

Leveraging Professional Lawn Care Services

Despite best efforts, lawn diseases can sometimes prove stubborn. In such cases, don't hesitate to engage professional lawn care services. With their expert knowledge and experience, they can diagnose and treat lawn diseases efficiently, ensuring your lawn stays verdant and beautiful throughout the year.


While winter lawn care may seem daunting, equipped with knowledge about common diseases and effective lawn care strategies, it's a challenge that can be overcome. Remain vigilant for early signs of disease, act promptly, and you can enjoy a lush, healthy lawn irrespective of the season. And while we've covered off on many of the common lawn diseases, there's more! Don't forget we're only a call or email away if you need help and advice!

Now that you're armed with this information, we encourage you to apply these strategies to maintain the health and beauty of your lawns. Have you encountered any of these winter lawn diseases in your garden? Do you have additional tips on keeping Australian lawns healthy during winter? We'd love to hear about your experiences and suggestions. 


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