Why is my grass turning yellow

A lawn turning yellow can be an upsetting view. Nothing is more depressing for a homeowner than the loss of a lush green lawn.

What is the cause of yellow grass appearing on your lawn? What could be done to turn your grass green?

Before making plans on how to fix yellowing grass, it is important to know the main reasons for the grass blades turning yellow.

Here are a few of the most frequently cited reasons for yellow and dead grass.

We’ll also provide the most effective methods to tackle each problem.

Grass turning yellow
Yellowing grass

Overview of main causes

  • Incorrect fertilizer application
  • Dog urine
  • Overwatering
  • Lawn diseases
  • Your lawn has pest problems
  • Grass blades aren’t cut properly
  • Heatwaves

What causes yellowing grass?

Incorrect fertilizer application

A mistake in fertilizing your lawn could cause your lawn to become yellow.

Both adding not enough and too much fertilizer can harm your lawn.


Over-fertilizing your lawn can cause chemical burns which result in grass turning yellow or even dying. Similar to many plants (and even humans! ) grass has a pH that is preferred and any deviations from which can cause issues.

Be cautious when treating the nutritional deficiencies of your grass. Overnutrition is the most common cause of chemical burns that occur in the grass, and so putting down more fertilizer could make the problem worse.


Under-fertilization can result in grass turning yellow due to nutritional deficiencies. The most frequent cause is nitrogen and iron deficiency.

This is when organic matter or plants that have a high content of carbon is added to the soil. In addition, some organisms use nitrogen from soils to reduce carbon and could cause nitrogen deficiency when it doesn’t get replenished.

If you observe the entire lawn becoming yellow in the spring, your grass may be suffering from a nitrogen deficiency. In contrast, grass that is yellow only in small patches tends to be suffering from iron deficiency.

How to turn incorrectly fertilized grass green

It is possible to avoid this by using fertilizer correctly. Follow the guidelines on the label, and apply the right fertilizer for your season.

The needs of grass vary throughout the year, so fertilizers have different amounts of nitrogen, phosphorus, and potassium to meet their needs. It is possible to purchase a soil test kit that will tell you the specific deficit. Or you can hire a professional to perform a soil test for you.

It is also important to distribute fertilizer equally. This can help avoid chemical burns due to too much nitrogen and nutrient deficiencies in areas that are not being considered.

A way to accomplish this is to go slowly across your lawn using a spreader in a similar way you’d use it to mow. Be mindful when you finish every pass. This is the place where the majority of people accidentally spill fertilizer.

Dog Urine

Similar to the reason why over-fertilizing may turn grass yellow, dog urine may do the same.

Dog urine contains plenty of nitrogen, which can create chemical fires on your grass. Urine is also a problem for the soil’s pH.

Dogs are known to do their business in the same location throughout the day, which could make the issue worse.

Fortunately, this issue can be fixed by moving your dog somewhere else to do their business.

Additionally, there are nutritional supplements for dogs that assist in making their urine more grass-friendly

Urine spots are easily changed to green with patch and repair seed mix. Another option is to repair the patch by installing sod. Or you could apply dog urine neutralizer and apply it to the yellow grass.

A dog sitting on the grass
Puppy on a grass lawn

Reseeding dog urine spots

Sometimes, urine spots aren’t able to grow back, particularly if you wait too much time before applying a neutralizer for urine.

To avoid your lawn from dying and turning yellow after a dog pees in it, it is possible to keep your pet in your yard, and then apply a neutralizer to yellow spots right after they had peed.

You can also eliminate the dying and yellowing spots on your lawn by just reseeding or re-sowing your lawn even if the damage was already done.

Over-watering your lawn

A lawn that receives excessive amounts of water is not only susceptible to diseases but, it could also have problems with root growth. And these factors could result in the yellow grass.

The lawn that has been overwatered can change color because the soil with too much water doesn’t have enough oxygen or other nutrients to reach grass roots. In the end, roots won’t grow as deep to the earth, which makes your lawn prone to being damaged.

Watering the grass lawn with a hose
Person watering the lawn

It is best to water in such manner so that you can tell the soil’s top layer is dry.

The morning time for watering is the most ideal time of the daytime and it is essential for the water to absorb and for the grass blades to dry out in the sun.

In the ideal situation, grass will do with only 1 inch of water each week.

Be sure to note the condition of the soil you have in your yard. The grass that grows in clay soil will require less water than grass on sandy soil.

Make sure to water your lawn only as required. If you’re experiencing lots of rain and you see your grass turning yellow, it might be better to stop watering for a while before you can resume.

Most lawns are healthier when you water them 3 to 4 times per week. If this results in yellow spots, limit frequency to one or 2 times.

Reduce how much water you use when irrigating your lawn to the recommended amount for the grass type you have.

Different types of grass require different routines for watering. And certain grass varieties are more drought-resistant and are cultivated with less water. St Augustine grass turning yellow could indicate fungal infection or waterlogged soil.

To avoid this, talk to a lawn expert to guide you and tell you the correct maintenance schedule that is appropriate for your grass in order to eliminate the yellow spots that appear on your lawn.

Lawn diseases

A yellow lawn is often a sign of a bacterial disease.

The majority of lawn diseases are usually fungal diseases. These include the fairy rings and dollar spot, snow mold, fusarium.

In addition to the yellow grass, you might also see the appearance of either black or white powder. These conditions typically develop when there is excessive moisture. The excess moisture could result from excessive watering, overwatering at night or the accumulation of an overly thick layer of thatch on your lawn (which keeps water from getting into the soil and keeps the grass wet instead).

Treating lawn diseases

The best way to stop the spread of disease to your lawn is to take proper care of it.

This means regular mowing, aeration, dethatching, and enough irrigation at the appropriate time.

To many aerations can seem like a redundant step, but it assists in the circulation of air beneath the soil and keeps your lawn from getting too wet. I suggest dethatching and aerating your lawn at least every 2 years to ensure the good condition and health of the lawn. In addition, you can overseed the lawn then top-dress it with compost at the same time to get the best results.

If your lawn is suffering from a persistent health issue despite having followed these steps, you may also decide to apply a fungicide during the spring.

It’s a fairly simple and cost-effective method that will eliminate any disease issues on your lawn.

However, remember that this only treats the issue but not the root causes. You’ll need to take action to ensure that the yellow grass does not return.

Your lawn has pest problems

Sometimes to find the reasons for grass turning yellow and dying you’ll have to inspect your lawn more closely.

The pests that make grass turn yellow can be difficult to recognize, but in the event that this is the cause, it’s crucial to determine the issue properly.

Worms will never be an issue on your lawn, but they can attract birds.

Bug living amog the grass
Small bug in the grass

Find any tiny bugs, eggs sacs as well as powdery or fuzzy coats on grass blades or holes in the soil that have been created by insects.

Insects can turn your lawn yellow and cause it to die due to feeding on the grass’s roots underneath the soil. They’re often unnoticed because they are harder to spot. In particular, chinch bugs are known to often cause lawn damage.

We would suggest digging one foot by 1-foot area of your lawn that is yellow to allow you to look at the soil and turf. You could also do this by cutting a “flap” into the lawn to see under the grass.

It is possible to replace the grass once you’ve completed your study and it will cause little damage if you don’t find any bugs (you’ll be able to lay the grass once more).

If you are suffering from grass grubs (this typically appears as brown spots but not as yellow) or another insect, there are methods to tackle the root cause.

Solving the pests problem

Our recommendation for treating the majority of pests is to buy and then apply beneficial nematodes to your lawn.

The worms are small enough to find and kill the soil pests for you. It’s an organic (and highly efficient) way to boost the health of your soil and address lawn problems. You can purchase them on the internet or you might be able to find them locally.

Grass blades aren’t cut properly

Another answer to the question “Why is my grass turning yellow?” could have to do with your equipment quality.

In the event that you find that your lawn begins to turn yellow after you’ve mowed your lawn, it could be due to worn-out mower blades.

Dull blades damage the grass by not cutting the edges of the grass blades properly. This makes the grass more susceptible to diseases.

It’s also dangerous when you mow grass that is wet because the grass clippings are likely to collide with the blade, creating an unbalanced cut.

How to cut grass properly?

The best solution to this problem is obviously to sharpen or replace the blades on your mower. It is possible to have the mower blades sharpened professionally or do it yourself. However, new blades aren’t that expensive and many homeowners feel more at ease buying a brand new pair.

Sharp mower blades ensure the highest quality trimming moving forward. You want to achieve a perfect cut that appears as you’ve snipped across the blades of grass.

Equipment for mowing the lawn
A lawnmower on grass

To get rid of yellow grass that was caused by a previous mower, you can adjust your mower’s deck lower in order to cut the damaged grass blades and for new greener plants to sprout up.

Make sure not to cut your lawn too close to your soil. This can be as detrimental to your lawn as a cut that is ragged. The ideal height for grass is around 2 inches or a bit more.

If you do decide to replace your mower’s blades, make sure you are careful. They are sharper than they appear. Wear gloves or long sleeves along with safety glasses. Remember to unplug the spark plug cable prior to when you start work in order to reduce the danger of shock.


In a few hot summer days, the grass could be burned and scorched to the point of being crisp. If this happens, since grass roots don’t get damaged due to the sunlight or the heat this means the grass is still healthy underneath its yellow skin. If you wait until the heat wave is gone and then gradually replenish the grass with the water it will recover.

One tip for watering in the summer or during the heatwave is not to use sprinklers. Sprinklers can only be used to water the surface levels of the soil and the moisture slowly evaporates. In this situation, the water must be able to reach the roots that are deeper at around 10 cm below surface level.

Sun shining on a grass lawn
Grass and sunshine


The yellow grass does not need to be a permanent feature in your garden. If you can identify the issue and stop it from getting worse, the discoloration could be swiftly stopped and reversed. Proper lawn maintenance and techniques are essential to maintaining keeping the lawn green, healthy and attractive and stopping it from turning yellow.

These good techniques, in conjunction with the knowledge of the root reasons, will speedily restore your yellow lawn to its former healthy appearance.

Leave a Comment