When you see your grass turning a shade lighter than green and closer to yellow, there’s a good chance that something is wrong and it should be addressed immediately.
According to a study by Siew-Wai Chin, a doctor of Philosophy focusing on horticulture and agronomy, yellowing – or the phenomenon where green grass turns yellow – is one of the visual symptoms of nutrient deficiencies. He used cow grass as a sample for his experiment. It was found that a nutrient deficiency caused the grass to show visual symptoms such as yellowing of the grass, emerging red or brown pigments, drooping of leaves, and growing of weeds.
Your grass is turning yellow and dying because it is lacking or has excess nutrients such as nitrogen, phosphorus, potassium, and iron. The best way to prevent grass nutritional deficiencies or a surplus is by correctly using lawn fertilizers.
However, this isn’t the only reason why your grass could be turning yellow and dying, other potential issues exist and I will go through them below.
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Why is My Grass Turning Yellow After Fertilizing?
Your grass can also turn yellow after you fertilize it. In this case, it is not due to nutrient deficiency but the excess of it. Most specifically, nitrogen.
Nitrogen is a vital element in the soil since it promotes a healthier, greener grass. However, in a study by The UMass Extension Turf Program, an excess of nitrogen, especially from fertilizers, can increase grass diseases, and an increased shoot growth while reducing root growth. It also reduces its susceptibility to extreme high and low temperatures and tolerance to stress and damage.
Therefore, even if it is advised to supplement grass growth with a nitrogen-rich fertilizer, you should not apply too much to avoid damaging its roots.
Why is My Grass Turning Yellow and Dying?
There are other reasons why your grass is turning yellow and dying aside from nutrient excess or deficiency.
Here’s a list of those reasons you may want to check or assess to determine the issue causing your yellowing or dying grass:
Grass Dryness and Dehydration
Dehydration caused by lack of water or too much heat can turn your grass yellow and eventually kill it, too.
The area on your lawn that is most exposed to the sun will most likely turn into yellow patches since they get exposed to heat compared to the rest of the lawn area.
Overwatering your Grass
Yes, to much water on and in your lawn can cause serious grass damage. I go into full details on “Why Is My Grass Turning Brown After Lot’s of Rain?”, check it out!
You may also have drainage problems in your lawn that need to be fixed, I also go into detail about “9 Ways How to Divert Water in Yard”. These ideas are great options for people of all lawn skill levels.
Your grass might be suffering from a fungal disease causing it to die and go yellow. The combination of heat from the sun and moisture from the water and soil makes it susceptible for fungi to grow.
Some common diseases that can infect and turn your grass yellow are smut, snow mold, fusarium, and fairy wings.
Pests and Insects Damaging Your Lawn
When you see your grass having yellow or dead patches, try to check if pests or other harmful insects are chewing off your grass. Their existence in your lawn can cause root damage and malfunction.
You can check this by getting a single grass blade and use a magnifying glass and see if you can spot any insect or larvae. It is better to know what pest you’re up against to amend the damage with the right pesticide.
Lawn Mower Problems
Your mower can cause problems for your yard. It could be because of a gas leak or because its blades are not sharp enough.
Petrol or gasoline is a strong chemical that can burn your grass. Prevent any spill at all costs since it is a very damaging chemical that does not only affect the grass but even down to its roots.
Dull blades can also cause damage to your lawn. When a lawnmower has a dull blade, instead of cutting the grass it pulls it from its roots. This causes root growth issues which can cause the grass to turn yellow and, in worse cases it can eventually die.
Soil compaction or physical damage to the lawn is also one of the reasons why your grass could be turning yellow. The constant pressure on it compacts the ground that prevents moisture and air from entering the roots. It can also damage the roots altogether.
Compaction is also caused by play equipment such as slip-and-slide, bikes, and other big and bulky toys that may run over your grass. Try to avoid traffic of all kinds on your lawn!
How to Prevent Grass from Turning Yellow and Dying?
Based on the causes stated above, here are some preventive measures so that your grass won’t turn yellow or die.
Preventing Excess Nitrogen and Nutritional Deficiencies
The best way to prevent the excess of nitrogen or the lack of nutrients in your soil is to have your soil tested so you can apply the right amount of fertilizer on it.
Once you get the test results, check the numbers on your fertilizer to know its NPK (Nitrogen, Phosphorus, Potassium) ratio that addresses the need in your soil based on the test. It usually has three numbers indicated on its package (for example 20-20-20) which gives you the idea on how much nitrogen, phosphorus, and potassium are in it. The best way to test soil is by using a testing kit where you send in soil and get results back. The Soil Savvy kit is a popular choice when lawn owners are looking to test their lawns.
Apply just the right amount of fertilizer. It should be between one-half or a pound per 1,000 square feet.
Aerate, Dethatch, and Keep from Heavy Traffic
Dethatching and aerating your soil can help prevent it from yellowing or dying.
Fungal diseases often come from lawns that are too compacted or filled with thatch. To prevent this, water your plants in the morning instead of late afternoon or during the night. This ensures that the sun’s heat can still absorb any excess water compared to just having the water sit overnight.
Also, clear your lawn from any grass clippings and other trash or debris that might trap the moisture under it.
Avoid compacted soil by keeping play equipment away from it. If you want a playset at least set a specific area for it that’s a few feet away from the grass in your lawn. Another option for a playset would be to create a gravel pit so you prevent fungi growing inbetween.
If you observe a particular pattern of yellowed grass caused by heavy foot traffic, create a pathway instead.
Check Mower for Maintenance
Have your mower checked regularly. Make sure that the gas tank doesn’t leak so it won’t damage the grass when you mow.
Also, make sure the blades are sharp and can cut through the grass properly. Like mentioned above, a dull blade will rip your grass up from the roots causing serious lawn damage.
Reviving Your Lawn When It Turns Yellow
Preventing any damage is always better than trying to fix it. However, when the damage is done, you have no choice but to try your best to revive your lawn.
The ‘first aid’ to any grass damage is water. Whether it’s excess or lack of nutrients or excess heat, you need to water the damaged area as soon as you notice it.
You can fix the damage on your lawn by using restorative fertilizers like Safer Brand’s Lawn Restore. It is plant-based and is completely safe for both humans and pets even after its application. This helps your grass to recover from any damage and stress caused by heavy traffic. It also promotes healthy growth as it improves.
But if the grass damage was because of pests and other insects, you can use Spectracide Triazicide Insect Killer. It kills both above-ground and below-ground parasites to stop them from preying on your grass. It is also safe to use, so it does not harm your lawn at all.
Make sure always to read the label and instructions when using both restorative fertilizers and pesticides on your grass. Read on the required dosage and application so you can apply just enough of it to revive your lawn and make it green again.
Keep Your Grass Green and Healthy!
Keeping your grass healthy entails a big responsibility and a lot of work. I hope these tips help answer “why is my grass turning yellow and dying”, figuring out a solution fast can save your lawn!
You need to keep the right balance of nutrients by choosing the right fertilizer, water them enough (but not too much) at the right time of the day, and make sure it does not get too damaged. If possible, prevent any damages!
It is always best to prevent any grass damage before they start to turn yellow or die. However, if the damage is done, early detection of its cause and immediately acting upon it is the key to reviving your lawn back to its green and healthy state.
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.