FAQ: Why is My Grass Yellow?

Watching the leaves change color in the fall can be a dreamy experience. But when you see your lawn turning yellow, that's a different story. A yellow lawn is often less about seasonal beauty and more about a potential problem with your grass health. Grass turning yellow can be frustrating, as it can signify an underlying issue that needs addressing. Yellowing grass is not something to ignore—fixing it promptly is essential to restoring your beautiful green lawn.

Key Takeaways

• Grass can turn yellow for various reasons, including pests, lawn diseases, nutrient imbalances, improper watering, and excessive thatch. Identifying the cause is crucial for implementing the right maintenance strategies to keep your lawn vibrant and healthy.
• To prevent yellowing, ensure proper watering, aerate compacted soil, and mow at the appropriate height with sharp blades. Also, maintain a thick, healthy lawn that chokes out weeds and regularly monitors for pests or diseases.
• For areas with dead or severely damaged grass, consider replacing them with premium-quality grass sod for sale from Bethel Farms. Sod installation offers faster establishment and resilience compared to traditional seeding, helping rejuvenate your lawn with varieties suited to your local growing conditions.

12 Reasons Your Grass Is Yellow

When the grass turns yellow, it’s usually a sign that something in its environment or maintenance routine isn’t quite right. This discoloration can result from factors such as pests, lawn diseases, nutrient imbalances, or simply dormancy. Each factor requires a different approach to remedy. Identifying why your grass is yellow is key to implementing a lawn maintenance plan that retains its green color and helps maintain a lush, healthy yard. Let’s look at the most common reasons your grass blades may be turning yellow and how to fix them.

1. Pests

Pests like grubs and chinch bugs are known for causing yellow grass. They feed on the roots or blades of the grass, causing it to weaken and turn yellow. Grubs, in particular, can cause entire sections of your lawn to lift easily like a carpet, revealing the damage they’ve caused underneath. If your lawn is wilting or showing random patches of yellow despite proper watering, you may have a pest issue. Check by lifting sections of sod to look for grubs or by inspecting the grass blades closely for signs of chinch bugs. Use a targeted pesticide or introduce beneficial nematodes as a natural remedy to eliminate grubs and chinch bugs. Regularly inspect your lawn for pest activity to prevent future infestations.

2. Lawn Diseases

Fungal diseases like dollar spot and brown patch can also cause grass to turn yellow, usually in circular or irregular patterns. Excessive moisture, humidity, and poor drainage create the perfect environment for these diseases to thrive. Look for yellow spots, rings, or patches on your lawn, especially during humid conditions. If you see yellow grass surrounded by a thin, white web-like growth, it’s likely a sign of fungal disease.

Apply a fungicide treatment, improve lawn drainage, and reduce watering frequency. Additionally, avoid watering late in the day, as prolonged moisture on grass blades promotes disease development.

3. Too Much or Too Little Fertilizer

Fertilizing your lawn helps keep it green and healthy, but an imbalance can have the opposite effect. Too much nitrogen can burn your grass, while too little can cause poor growth, leading to yellow patches.

Although optional, a soil test can help assess nutrient levels and guide fertilizer application. Use a balanced, slow-release fertilizer to maintain consistent soil health and prevent nutrient imbalances that turn your lawn yellow.

4. Dog Urine

Dog urine contains ammonia, which is high in nitrogen. In concentrated amounts, this can cause random yellow spots on your lawn. When urine seeps into the soil, the ammonia is absorbed by the roots and carried to the blades, burning the grass. This effect is similar to over-fertilization, resulting in discoloration and potential damage.

If your dog regularly uses the lawn as a bathroom, supervise it while it’s outside. This way, you can water the spot immediately after they go, diluting the nitrogen and preventing fertilizer burn. Alternatively, consider using grass potty pads for dogs, which provide a designated area for bathroom breaks and help protect your lawn from damage.

5. Improper Watering

Overwatering and underwatering are two common but often overlooked reasons why grass turns yellow. Most warm-season grasses require about 1 to 1.5 inches of water per week, ideally spread over 1-2 sessions. Too much water can lead to root rot, while too little causes dehydration and yellowing.

Water deeply but infrequently until the soil is moist 6-8 inches deep to promote strong root growth. Signs of underwatering include wilting or a blue-gray tint while overwatering can cause soggy soil and fungal growth. Adjust your watering schedule based on these indicators to keep your lawn healthy and green.

6. Compacted Soil

Soil naturally becomes compacted over time due to heavy foot traffic, the use of heavy equipment, or simply from the soil settling. When soil is compacted, it restricts root growth and prevents water, air, and nutrients from reaching the roots. This leads to weakened, yellow grass blades as the grass struggles to thrive.

Address soil compaction by aerating your lawn using a core aerator. This process helps relieve compaction and improves soil structure, allowing for better air and water movement. Regular aeration is essential for maintaining a healthy lawn and preventing yellowing grass.

7. Improper Mowing Practices

Mowing too low, using dull mower blades, or cutting grass when wet can stress the lawn and cause yellowing. Scalping exposes the soil to direct sunlight, while dull blades tear instead of cut, damaging the grass.
Set your mower blades to the highest recommended height for your grass type during hot weather to provide shade to the soil. Keep mower blades sharp, and avoid mowing when the grass is wet to prevent damage.

8. Too Much Shade

Warm-season grasses like Bermuda thrive in full sun and struggle in shady areas, leading to yellowing due to a lack of sunlight. Trim back trees and shrubs to increase sunlight exposure, or consider replacing the affected areas with a more shade-tolerant variety, such as St. Augustine grass. Read our guide on how to grow grass in the shade.

9. Invasive Weed Growth

Weeds compete with grass for nutrients, sunlight, and water, causing your lawn to turn yellow as the desired grass species struggle to survive. To prevent conditions conducive to weed growth, it's important to maintain a thick, healthy lawn that effectively chokes out weeds by mowing at the right height, watering deeply but infrequently, and regularly fertilizing to encourage dense growth.

If you have excessive weed growth, apply a selective herbicide to target it or manually remove it to reduce competition and allow your grass to recover.

10. Excessive Thatch

Thatch is a layer of dead grass and other organic matter that forms on the soil surface. While a thin layer—up to half an inch—is beneficial by insulating the soil and reducing moisture loss, too much thatch can act as a barrier, preventing water, air, and nutrients from reaching the roots. This restriction leads to yellow grass and poor overall lawn health.

To dethatch, use a power rake or a dethatching rake to break up the thatch layer and remove the excess buildup. Regular lawn aeration also helps reduce thatch and maintains a balanced layer for optimal lawn health.

11. Dormancy

Warm-season grasses like Bermuda and Zoysia naturally go dormant when soil temperatures drop below 55°F, typically in late fall or early winter. During this period, the grass turns yellow or brown as a way to conserve energy and protect itself from the cold. It’s important to differentiate between dormant and dead grass: dormant grass still has the roots intact and will return to its green state when the conditions become favorable again, while dead grass has no chance of revival. You can check if your grass is dormant by gently tugging on the blades—if they resist and stay rooted, your lawn is dormant. If the blades pull away easily, the grass may be dead.

Allow your lawn to rest during its dormancy period, avoiding the urge to fertilize or overwater. When temperatures consistently warm up in early spring, resume regular lawn care, such as mowing and feeding.

12. Dead or Dying Grass

Grass that is dead or severely damaged will not recover on its own. This can happen due to prolonged periods of stress, such as drought, extreme heat, or pest infestations. Other factors include neglect, such as improper mowing, over-fertilization, or lack of water. Dead grass appears brittle and pulls away easily from the soil, while the roots will be dry and brittle. Unlike dormant grass, which will green up again, dead grass will not return and needs to be replaced.

If you suspect your lawn has dead patches, it’s better to remove these areas and start fresh. Replanting grass through sod installation facilitates faster establishment than traditional seeding, making them excellent for rejuvenating dead grass or replacing your lawn with a variety more suited to your specific growing conditions.

Final Thoughts

Understanding why your grass is turning yellow is essential for maintaining a lush green lawn. From pests to poor watering practices and excessive thatch, identifying the underlying issues will allow you to take the proper steps toward recovery.

Bethel Farms is a trusted sod farm in Florida offering premium-quality grass sod cultivated to help you restore your lawn to its lush, green state. Visit our website today to get started.