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Tips for preventing lawn diseases 

Lawn diseases can quickly turn a flourishing green yard into a patchy, discoloured mess. However, you can protect your lawn from common grass diseases with the proper knowledge and preventative care.  

We’ll explore how to treat lawn disease, identify its causes, and highlight crucial prevention techniques to keep your lawn in top shape.

Looking to get a jump start on preventing lawn disease? Watch our video explaining ‘what is lawn disease?’ It explores common turf diseases and the most effective eradication tips. 

What causes lawn disease?

Lawn diseases are often caused by environmental stress, poor drainage, improper lawn care, and fungal pathogens. Fungal diseases, in particular, are a significant concern for turf grass species, as they thrive in specific weather conditions and can wreak havoc if left untreated.

Fungal lawn diseases tend to be more prevalent in periods of excess moisture, high humidity, or extended drought stress. Different turf species are susceptible to various turf diseases, so it’s important to understand what type of grass you have and the common diseases it may face.

Some key causes of lawn disease include:

• Poor drainage: Excess water encourages fungal growth, weakening the roots and promoting disease.
• Drought stress: Dry conditions can cause weakened turf, making it more susceptible to disease.
• Over-fertilisation or under-fertilisation: Imbalanced nutrition can create an environment where diseases thrive.
• Improper mowing: Cutting the grass too short or with dull blades can stress the grass blades, leaving them vulnerable to fungal diseases.

Understanding these factors is the first step in identifying lawn disease and preventing it from taking hold.

Common types of lawn diseases 

Winter Fusarium

Winter fusarium, also known as fusarium patch, is a common fungal disease that affects cool-season grasses. This disease thrives in cooler, wet conditions, making it a significant concern during winter.

How to identify Winter Fusarium:

• Look for small, circular patches of discoloured turf that can grow and merge over time.
• The affected areas may appear water-soaked, with the leaf blades turning yellow or reddish-brown.
• As the disease progresses, a white or pinkish fungal growth may appear on the surface of the turf, especially during damp conditions.

What causes the Winter Fusarium?

Winter fusarium typically develops in lawn areas with poor drainage and where thatch has accumulated. It can also be triggered by over-fertilisation in the late autumn, which encourages rapid grass growth at a time when the lawn should be slowing down for winter.

Prevention tips:

• Aerate your lawn to improve drainage and reduce compaction.
• Avoid applying too much nitrogen fertiliser late in the season.
• Do not overwater cool-season grasses during winter.

Dollar Spot

Dollar spot is another prevalent turf disease that primarily affects warm-season grasses, but it can also impact cool-season grasses. This disease gets its name from the silver-dollar-sized patches it creates on the lawn.

How to identify Dollar Spot:

• Small, circular patches of light-coloured grass appear, often less than 6 inches in diameter.
• The leaf blades will have tan or straw-coloured lesions with reddish-brown borders.
• As the disease progresses, these patches may merge, creating larger areas of affected turf.

What causes Dollar Spot?

Dollar spot is usually caused by extended periods of leaf wetness, such as heavy dew, high humidity, or overwatering. It is particularly problematic during warm days and cool nights when moisture sits on the grass for extended periods.

Prevention tips:

• Water your lawn early in the day to allow the grass to dry before nightfall.
• Mow your lawn regularly, but avoid cutting the grass too short.
• Keep your lawn properly fertilised, as Dollar Spot thrives in nutrient-deficient soils.

Red Thread

Red Thread is a fungal disease most common in cool-season turf species. It’s often seen in lawns that are undernourished or suffering from drought stress. This disease is easily recognisable by the pinkish-red strands it produces on the grass.

How to identify Red Thread:

• Patches of light brown or pink grass will appear, typically in irregular shapes.
• The distinctive red or pink threads of the fungus can be seen extending from the grass blades, especially in moist conditions.

What causes Red Thread?

Red Thread is often a sign of poor lawn health due to insufficient nitrogen. It tends to develop in lawns that are poorly maintained or in turf that is weakened by drought or stress.

Prevention tips:

• Maintain a balanced fertilisation program to ensure your lawn has enough nitrogen.
• Improve lawn drainage to prevent water from sitting on the surface of the grass.
• Aerate your lawn to reduce soil compaction and promote healthy root growth.

Prevention is key: How to prevent lawn disease

Prevention is the most effective method for keeping your lawn free from disease. While it’s important to know how to treat lawn disease if it occurs, implementing preventative strategies will reduce the risk of disease taking hold in the first place. Here are the key aspects of lawn disease prevention:

1. Regular aeration

Aerating your lawn improves soil structure, reduces compaction, and increases water infiltration. This helps prevent fungal diseases by ensuring that water doesn’t sit on the surface, creating conditions for diseases like dollar spot and red thread to thrive.

2. Proper watering practices

Water early in the morning to give your lawn time to dry throughout the day. Overwatering or watering late in the evening can leave your lawn vulnerable to diseases by creating prolonged periods of moisture. In particular, areas with poor drainage should be monitored closely, as standing water is a breeding ground for fungal lawn diseases.

3. Fertilisation and lawn nutrition

Ensuring your lawn has the right nutrients is crucial. Fertilise your lawn according to the needs of your specific turf grass species. Under-fertilising can lead to nutrient deficiencies, making the grass weak and more susceptible to turf diseases. Conversely, over-fertilising can encourage rapid growth, which also increases susceptibility to disease.

4. Mowing technique

Proper mowing is critical in preventing lawn disease. Always use sharp mower blades to avoid damaging the leaf blades, and don’t cut the grass too short. Scalping the lawn can stress the grass and leave it open to infection.

5. Identify lawn disease early

Knowing how to identify lawn disease is essential in preventing it from spreading. Keep an eye out for the telltale signs of disease, such as discoloured patches, irregular growth patterns, or visible fungal growth on the grass blades. Early intervention is key to stopping the disease in its tracks.

Keep your grass in top condition with help from Lilydale Instant Lawn 

By understanding what causes lawn disease and how to prevent it, you can maintain a healthy, vibrant lawn year-round. At Lilydale Instant Lawn, we stock a range of fertilisers, pesticides, and weed control products that will prevent your lawn from contracting diseases. Browse our online lawn care shop today. 

Remember, prevention is always better than cure. A well-maintained lawn is your best defence against fungal lawn disease, ensuring your grass remains green and healthy, even during challenging conditions. Stay vigilant, and your lawn will thank you!