Why Is My Grass Turning Yellow? 8 Problems & Solutions

It’s frustrating to watch a vibrant, green lawn fade to patches of yellow or tan, despite regular watering and mowing. Whether it’s Bermuda grass yellowing after a fertilizer application or St. Augustine grass turning pale after weed-killer use, the sight of a struggling lawn can leave homeowners puzzled. Yellow grass can stem from various issues—seasonal stressors, lawn diseases, or even compacted soil. If you’ve tried multiple fixes and still find yourself asking, “Why is my grass turning yellow?” it might be time to call in a professional lawn specialist. Below, we explore the common causes and practical solutions to restore your lawn’s lush appearance, with some added insights to help you prevent future problems.

Low Nutrient Levels Can Cause Grass to Turn Yellow

Like any plant, grass needs specific nutrients to thrive. Deficiencies in nitrogen, phosphorus, potassium, iron, magnesium, or even oxygen can cause yellowing. Nitrogen, in particular, is critical for that rich green color. If your lawn is turning yellow in spring or summer, it might need a nutrient boost through fertilizer or specialized lawn treatments. But don’t just grab any bag off the shelf—choose a fertilizer tailored to your grass type, and follow the application instructions carefully to avoid overdoing it.

Pro Tip: Soil testing can pinpoint exactly which nutrients your lawn lacks. Sending a sample to a local cooperative extension or a DIY lawn-care program can provide a customized plan, ensuring you’re not wasting time or money on the wrong products.

Overfertilizing Can Harm Your Lawn

More fertilizer doesn’t always mean better grass. Overfertilizing can stress your lawn, leading to yellow or brown patches. The best fertilizers match your grass type and come with clear guidelines on how much to apply and when. Spreading fertilizer evenly prevents nutrient overload in one spot, which can burn the grass. If you’ve already applied too much granular fertilizer, try scooping up the excess with a shovel. For liquid fertilizers, rinse the area with water over a week to flush out the buildup. If the grass doesn’t recover after a few weeks, reseeding may be necessary.

Added Insight: Consider slow-release fertilizers for a gentler nutrient delivery. They reduce the risk of fertilizer burn and provide steady nourishment, especially for lawns recovering from stress. Always water lightly after application to help the nutrients soak in without overwhelming the soil.

Improper Fertilizer Application Leads to Yellow Grass

Fertilizers, especially fast-acting liquid ones, contain soluble salts that can accumulate and turn grass yellow if applied incorrectly. Uneven application, over-concentration, or using the wrong tool can create yellow or bare spots. If you notice tan or yellow patches, water the area consistently for about a week to dilute the salts. If the grass doesn’t bounce back after a few weeks, you may need to dig up the affected areas and reseed.

Overwatering or Underwatering Can Cause Yellowing

It’s easy to assume more water equals a healthier lawn, but overwatering can drown grass roots, reducing oxygen in the soil and causing yellow patches. Conversely, underwatering can mimic drought conditions, leading to yellow or dead grass. To fix this, adjust your watering routine—focus on the yellow patches, and water when temperatures are cooler, like early morning or late afternoon. Most mature lawns need only about 1 to 1½ inches of water per week.

Practical Note: Use a rain gauge or a small container to measure how much water your sprinkler delivers. This helps you avoid guesswork and ensures your lawn gets just the right amount. If you’re dealing with overwatering, let the soil dry out a bit before resuming a balanced schedule.

Lawn Diseases and Pests Can Turn Grass Yellow

Sometimes, yellow grass has little to do with your care routine and more to do with pests or diseases. Look for small holes in grass blades, which could indicate insects like caterpillars, beetle grubs, or worms eating the roots. If pests aren’t the issue, lawn diseases like mold or fungus might be to blame. Common culprits include:

• Dollar spot: Small, circular, sunken patches with white spots on blades.
• Fairy ring: Circular rings of dark green and dead grass, often with mushrooms.
• Take-all root rot: Short, rotted, black roots.
• Brown patch: Circular patches of brown grass with gray or brown spots on blades.
• Large patch: Similar to brown patch but without lesions on leaves.
• Rust: Yellow to orange powdery substance on blades that rubs off easily.
• Leaf spot or melting out: Dark spots with a yellow ring.
• Gray leaf spot: Brown to gray oval spots, common on St. Augustine grass in summer.
• Anthracnose: Reddish-brown spots with a yellow halo.
• Slime mold: Slimy or crusty pinhead-sized balls, easily removed.
• Pythium root rot: Mottled leaves and slow-growing grass.

To combat fungal diseases, adjust your watering to avoid excess moisture, remove grass clippings after mowing, or apply a fungicide to affected areas. For persistent issues, a lawn care professional can diagnose and treat the problem effectively.

Extra Tip: Aerating your lawn annually can improve air circulation and reduce the conditions that foster fungal growth. Pair this with proper mowing height—keeping grass slightly longer—to promote stronger roots and resilience against diseases.

Dog Urine Can Create Yellow Spots

Dog urine is a common culprit for yellow lawn spots, thanks to the ammonia and chemicals it contains. These can burn grass, leaving dead patches. The fix is straightforward: apply horticultural lime to the affected areas, following the product’s instructions, and water thoroughly afterward. The spot should turn green within a few weeks. If it doesn’t, dig out the dead grass and reseed.

Prevention Note: Train your dog to use a specific area of the yard, like a gravel or mulch patch, to minimize damage. Regularly rinsing urine spots with water right after your dog goes can also prevent yellowing before it starts.

Compacted Soil Leads to Yellow or Brown Grass

Frequent foot or vehicle traffic can compact soil, squeezing out the space needed for oxygen, water, and nutrients to reach grass roots. This often results in yellow or brown strips along paths or driveways. To revive these areas, try adding compost to enrich the soil or aerating to loosen it. For severe cases, a professional lawn care service can assess and treat the soil effectively.

Seasonal Stressors Can Cause Yellowing

Extreme temperatures—whether scorching heat or freezing cold—can stress grass, causing it to yellow. Many grass types enter a dormant state during summer or winter to survive harsh conditions, turning grayish or straw-colored. Residual salt from de-icing sidewalks or driveways can also contribute. “By the end of the summer, grass that’s been overexposed to heat and drought may go dormant just to survive until spring,” says Frank Rossi, chief science officer at Sunday Lawn Care. While this is normal, maintaining a consistent lawn-care routine can reduce stress and help your grass recover faster.

Seasonal Advice: In hot climates, consider planting warm-season grasses like Bermuda or Zoysia, which handle heat better. In colder regions, cool-season grasses like fescue or bluegrass are more resilient. Adjusting your lawn care to the season—less water in cooler months, more shade in summer—can make a big difference.

Frequently Asked Questions

Why is my grass turning yellow in summer? Excessive heat and full sun exposure can dry out your lawn, causing yellowing in warmer seasons.

Why is my grass turning yellow in winter? Grass often goes dormant in cold months, turning yellow to protect itself from snow or ice.

Why is my grass turning yellow over my drain field? Yellow strips over a drain field may indicate a leaking septic line or drying from warm temperatures.

Why is my new grass turning yellow? Cutting new grass too short can cause moisture loss, leading to yellowing. Let it grow longer before mowing to retain water.

What’s the best fertilizer for yellow grass? It depends on your soil. A soil test from a cooperative extension or DIY lawn-care program can recommend the right fertilizer for your needs.

Why is my grass turning yellow even after watering? Overwatering may be drowning the roots, reducing oxygen and causing yellow patches.

Does grass turn yellow with too much water? Yes, overwatering can suffocate roots and lead to yellowing.

Is it normal for grass to turn yellow in summer? Yes, especially in warm climates where heat and sun stress the lawn, causing it to dry out.

Yellow grass can be a headache, but with the right approach—whether it’s tweaking your watering habits, addressing nutrient deficiencies, or tackling pests—you can often bring your lawn back to life. For persistent issues, don’t hesitate to consult a professional to get your yard back to its green glory.