Why Lawns Turn Yellow: Common Causes

Why Lawns Turn Yellow: Common Causes

Why Lawns Turn Yellow

It’s unusual for lawns to have yellow patches through the summer period, however, this can be a result of a few factors including nutrient deficiencies, improper watering, pests and diseases. By identifying the specific cause, you can take appropriate steps to address the issue, ensuring your lawn remains healthy throughout the year.

Common Causes of Yellow Lawns

A lush, green lawn is the pride of any homeowner. However, when your lawn turns yellow, it can be quite distressing.

One primary reason why a lawn can yellow after we have lots of rain is essential nutrients can leach through the soil, leaving the grass hungry. Grass needs nutrients to thrive, when these nutrients are insufficient, the grass can turn yellow. To ensure your lawn receives the necessary nutrients, consider using a high-quality lawn fertiliser such as those applied by GreenThumb.

Excessive rain can also cause yellow lawns due to waterlogged soil; this will deprive the grass roots of the necessary air it needs. This can make the soil anaerobic, as the grass is unable to absorb nutrients resulting in yellowing, due to lawn stress.

Leaf spot on lawn

Wet conditions are also conducive to fungal growth. Diseases such as leaf spot seen regularly in summer months can be a cause of yellowing. Another potential disease, Microdochium Patch can also cause yellow patches in the lawn.

Rain can be also associated with cooler weather. Sudden temperature drops can stress warm-season grasses, causing them to turn yellow.

Improper watering is another leading cause of yellow lawns. Both overwatering and underwatering can stress the grass, causing it to turn yellow. Water your lawn correctly when necessary allowing the water to penetrate the soil and reach the roots. Avoid watering during the hottest part of the day to minimise evaporation. We offer expert advice on proper watering techniques to help you maintain a healthy, green lawn in our watering blog.

Chafer Grub in Lawn

Pest infestations can also lead to yellow lawns. Common pests like Chafer Grubs and Leatherjackets can damage the grass by feeding on its roots or blades, resulting in yellow patches. If you suspect a pest infestation, take immediate action, contact us today, we provide effective pest control solutions to reduce their populations and help to restore your lawn's health.

Preventing Yellow Patches on Your Lawn

Maintaining a healthy and vibrant lawn requires regular maintenance and proper care. If you've noticed yellow patches on your lawn, don't worry. There are steps you can take to prevent this from happening. Here are some tips to help you maintain a lush, green lawn:

Lawn mowing a GreenThumb lawn

Regular Lawn Maintenance: Mowing your lawn regularly and at the correct height is essential for preventing yellow patches. Set your mower blades to a height of around 1-2 inches (2.5-5 cm). This allows the grass to grow taller, promoting stronger root development and helping to shade the soil, reducing the risk of yellowing.

Proper Fertilisation Schedules: Fertilising your lawn is crucial for providing it with the essential nutrients it needs to thrive. However, over-fertilisation or using the wrong type of fertiliser can lead to yellow patches. Follow a proper fertilisation schedule, applying the right amount of fertiliser at the recommended times of the year, this is where we come in. We will ensure your lawn receives the necessary nutrients without causing damage.

Watering Grass with Sprinkler

Effective Watering Practices: Watering your lawn correctly is vital for its overall health. Overwatering can suffocate the roots and this causes yellowing and promotes disease, while underwatering can also cause stress which will lead to yellowing.

Restoring Your Lawn's Green Colour

When your lawn turns yellow, it can be a frustrating sight. However, with the right care and attention, you can restore its vibrant green colour. Here are a few effective methods to help revive your yellowing lawn:

A hand dropping lawn seed on a lawn

Reseeding and Overseeding: If your lawn has large patches of yellow or bare areas, reseeding or overseeding can be a great solution. Reseeding involves spreading grass seed over the entire lawn, while overseeding targets specific areas. This helps fill in the gaps and promote new grass growth, resulting in a healthier and greener lawn.


Using Lawn Tonics: Lawn tonics such as StressBeater are specially formulated fertilisers that provide essential nutrients for your lawn. These tonics contain a balanced blend of nitrogen, micronutrients, amino acids, bio stimulants and wetting agents which are crucial for healthy grass growth. By regularly applying lawn tonics, as directed, you can supply your lawn with the nutrients it needs to regain its green colour.

Seasonal Considerations for Lawn Care

When it comes to maintaining a lush, green lawn in the UK, it's important to consider the seasons that can affect its health and appearance. Here are three key factors to keep in mind:

Winter Dormancy Effects: During the colder months, lawns in the UK often go into a state of dormancy. This means that the grass slows down its growth and may turn yellow. It's important not to panic during this time, as it is a natural response to the colder temperatures. However, it's still important to continue basic lawn care practices, such as regular mowing, feeding and clearing any debris that may accumulate on the surface.

Summer Heat Stress: The UK may not be known for scorching hot summers, but even moderate heat can cause stress to lawns. When temperatures rise, lawns can become dehydrated and turn yellow or brown. To combat this, it's important to water your lawn regularly, allowing the water to penetrate the soil and reach the roots.

Autumn Lawn Preparations: As summer comes to an end, it's time to start preparing your lawn for the colder months ahead. One important step is to aerate the soil, which helps to alleviate compaction and improve drainage. This allows air, water, and nutrients to reach the grass roots more effectively. Additionally, consider overseeding your lawn to fill in any bare patches and promote healthy growth. Finally, adjust your mowing height to 25mm (1”) this will help to keep the lawn healthy and tidy.

By understanding and addressing these seasonal considerations, you can maintain a vibrant, green lawn throughout the year.

Common Mistakes to Avoid

When it comes to maintaining a lush green lawn in the UK, there are a few common mistakes that many homeowners make. By avoiding these mistakes, you can ensure that your lawn stays healthy and vibrant throughout the year. Let's look at some of these mistakes:

Close mowing: One of the most common mistakes people make is to cut their lawn too short. While it's important to keep your lawn trimmed, cutting it too short can lead to stress and weaken the grass. It's recommended to only cut one-quarter of the grass blade length at a time to maintain its health.

fertiliser burnt lawn

Incorrect Fertiliser Application: Applying fertiliser incorrectly can also cause your lawn to turn yellow. Over-fertilisation can burn the grass, while under-fertilisation can result in nutrient deficiencies. 

Ignoring Soil Compaction: Soil compaction occurs when the soil becomes tightly packed, making it difficult for air, water, and nutrients to penetrate the roots. Ignoring soil compaction can lead to yellowing of the lawn. Regular aeration can help alleviate compaction and improve the overall health of your lawn.

If you need further assistance or advice, don't hesitate to reach out to us at GreenThumb. We offer a range of lawn care services designed to keep your lawn looking its best.

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