Yellow Grass: Causes and Treatment
Yellow grass is a depressing sight for anyone who has a lawn. A luscious green lawn keeps the homeowner happy and satisfied, but seeing your lawn turn yellow can be disheartening, especially when you don’t know the reason behind it.
In this article, Edenapp will be answering all the questions you might have regarding yellow grass – its causes and how to fix it. We’ll also be shedding light on how to protect your lawn grass from losing its color, so let’s dive right into it!
What Causes Grass to Turn Yellow?
Some common causes of lawn grass losing its color and turning yellow are lack of nutrients, climate change, some diseases, or insects and lawn dormancy. But some lesser-known reasons also cause a significant change in the color of your lawn and lead to yellow patches on the grass.
Edenapp brings you all these causes below:
Too Much Shade
You might have noticed that the grass in certain areas of your landscape turns yellow or loses color more often than the rest of your lawn. This might be an area where the sunlight does not reach properly. Too much shade leaves less room for the grass to receive enough sunlight. Grass needs a certain amount of sunlight to grow healthy and lush.
Grass that does not receive adequate sunlight loses its density, starts thinning out and becomes prone to diseases as well.
But this is not a cause you need to worry about too much, as with a few adjustments, your grass will start turning green again:
- Prune trees that are blocking sunlight from reaching that area.
- Don’t water the area too much. Shady areas tend to have low evaporation rates as there isn’t enough sunlight. So watering too often will lead to water stress on the roots.
- Increase the mowing height of your lawnmower, so that shade grass grows taller.
- Overseed this area with a grass type that complements the existing grass and is shade-tolerant.
You will need the right type of pruning equipment to prune your trees and a lawnmower to make the mentioned adjustments. Tree care should be performed by experts. Therefore, Edenapp suggests hiring a certified arborist to prune the tree that is blocking the sunlight without harming it.
If you own a pet (specifically a dog), this could be one of the reasons why your lawn is losing its color. Those yellow patches in your grass that make it come off as dry and unhealthy might be because of your dog’s urine.
Dog urine contains urea, which has a nitrogen content, too much of which will eventually result in the death of your grass. That’s why it’s essential to notice the peeing habits of your dog. If it’s peeing in the same spot repeatedly, then the nitrogen in its urine will cause the grass in that spot to become dry and yellow, ultimately killing it if the situation continues.
But the thing that most people might be thinking is, ‘How do we stop our dog from peeing on the same spot over and over again?’ Don’t worry; Edenapp has got you covered here.
Here are a few simple tips on how to fix dog urine spots on lawns:
- Change your dog’s diet: Consult with your vet and modify your dog’s diet to include more fresh proteins than processed proteins. This will reduce the nitrogen content in its urine.
- Keep a watch on your dog and thoroughly rinse or wash off the area as soon as it finishes its bathroom break.
- You could use positive reinforcement to train your dog to do its business away from the lawn and in an area that is easy to clean.
- If the grass is damaged, you should remove the dead grass and overseed the affected area with grass types that are more resistant to animal urine, like Fescues and Perennial Ryegrasses.
If this issue remains unchecked for a long period, then the nitrogen from the urine will start tricking into nearby grass spots and start affecting them as well.
Grubs and Chinch Bugs
Grubs and Chinch bugs are insect species that snack on grassroots. Grubs are the larvae of adult beetles. It is important to note that the damage to grass is caused by larvae and not adults. The grubs develop into adults in three stages, and during this entire time, they will feed on the roots of your grass, making them turn yellow and then brown. The most damage is caused during the summer.
Chinch bugs are another type of lawn pest that is most prevalent on St. Augustinegrass. They damage the grass by sucking out its fluids with their mouths and injecting a toxin into the grass, turning it yellow.
The damage caused by these insects is similar to that of drought. A noticeable trait is your grass turning from yellow to brown, which eventually results in the grass dying. This is a widespread phenomenon in the United States starting from April and lasting till October, but in Florida, they are prevalent all year round as the temperature conditions are favorable to them.
It is important to detect these pests in the early stages of infestation to avoid widespread damage to your lawn, as it might prove expensive to repair.
Tips to get rid of Chinch Bugs and Grubs:
- Inspect your grass for the presence of these pests frequently.
- Take good care of your yard and water your grass regularly.
- Avoid thatch buildup, as thatch encourages these pests.
- Aerate your soil.
- Fertilize when needed, as grass that receives adequate nutrients is healthy and tolerant to pest infestation.
- If the infestation is already at a critical stage, consult a professional pest control operator so that they can develop the right pest control program for your lawn.
Nitrogen is the nutrient responsible for the lush, green color that makes your grass look healthy. The lack of nitrogen in your grass will lead your turf to turn yellow. To determine nitrogen levels in your grass, you can conduct a simple soil test at home or consult a professional or your local county extension office if you want an expert opinion. A professional soil test will reveal the percentage of nitrogen deficiency and also mention ways to fix it.
Nitrogen-deficient lawns can also be identified by the presence of clovers in the lawn, as they are prevalent on soils with inadequate nitrogen content.
There are two ways to fix nitrogen deficiency in your lawns:
- Organic measures – Adding composted manure to the soil and planting vegetable plants like peas and beans that can fix the nitrogen content of the soil, are good, environmentally friendly ways to correct nitrogen deficiency, even if they are slow to act. These measures also have a long-lasting effect on your lawn.
- Non-organic Methods – Adding chemical fertilizers with a high proportion of nitrogen in the NPK ratio (Nitrogen (N), Phosphorus(P), Potassium(K)) is another way to correct nitrogen deficiency. These fertilizers will give a good, strong boost of nitrogen to the soil, but they also get used up or washed away very quickly. A point to consider when applying NPK fertilizers is that the use of phosphorus is regulated in some states of the U.S., and states like Florida also have a fertilizer blackout period. Therefore, you should check your local ordinances before the application of chemical fertilizers.
Dull Mower Blades
Your grass is put under stress every time it is cut, but if the cuts are clean, the grass can recover from it and continue to grow in a healthy manner. But dull mower blades do not cut your grass cleanly. Instead, they rip off or tear the grass blades. If you inspect your grass closely after mowing, you will see that the ends of the blades are rough. This is an indication that your mower blades have become dull and need to be sharpened.
Dull mower blades damage the grass that remains after mowing, causing it too much stress to recover from. Thus, the grass starts turning yellow. The tolerance of the grass also gets lowered in this case, making it more susceptible to disease and pest infestation.
The solution to this is to sharpen your mower blades regularly. One might wonder how often they need to do this. Mower blades tend to become dull after three hours of operation. Therefore, if it takes you 30 minutes to mow your lawn, and you cut your grass every five to six days, then you should sharpen your blades once a month. If the blade is too worn, then you should replace it.
You’re Cutting the Grass too Short
Cutting the grass too short might lead to the scalping of your lawn. Ultimately the grass will not be able to photosynthesize, will lack moisture and will turn yellow. This could be because your mower’s mowing blade is too low.
A simple fix to prevent your grass from being cut too short is to move your mower’s mowing blade a little higher. If you keep cutting your grass shorter than recommended, your grass will become weak and prone to weeds, diseases and pest and insect infestation because it cannot photosynthesize at that length. Therefore, you should raise your mowing height as soon as you notice a pattern of your turfgrass turning yellow after mowing.
Remember to never cut more than ⅓ rd of the grass blade’s height during a single mow as it causes undue stress on the sheaths of the grass blades, leaving them weak and vulnerable. Also, different grass types have different recommended heights. Some examples are given below:
- Zoysiagrass: 1 to 2 inches
- Fescue (both tall and fine): 2 to 3 inches
- Kentucky Bluegrass: 2.5 to 3.5 inches
- Bahiagrass: 3 to 4 inches
- St. Augustine Grass: 2.5 to 3 inches
Dormancy is a phenomenon where your grass turns yellow to protect itself to tolerate weather conditions that are not favorable for its growth. The dormancy period depends on the type of your grass.
Cool-season grass like Fescue and Kentucky Bluegrass has two dormancy periods – summer and when the temperatures drop below 45 degrees Fahrenheit during winter. Cool-season grass cannot tolerate the heat of summer well; therefore, they go into a state of dormancy where they turn brown to conserve all their energy for essential survival processes only.
When the temperatures are in the 80 degrees Fahrenheit range, the grass can survive in its summer dormancy state for three to four weeks, but when the temperatures reach the 90 degrees range, the grass can survive in this dormant state for only about two weeks. If the high temperatures prolong, then the grass can die if sufficient irrigation is not provided.
During this period, you need to irrigate your grass lightly every few weeks to ensure it survives the dry season. Make sure you don’t overwater your grass when it is dormant, as all the water will not get absorbed.
For warm-season grass like Bermuda Grass and Zoysia, there is only one dormancy period in winters. Warm-season grass can tolerate high temperatures, and therefore they stay active and green during the summer months. But when the temperatures dip below 55 degrees Fahrenheit, they enter winter dormancy to protect themselves against the cold weather. This is why southern lawns in America lose color and turn brown during the winter.
It is important to note that, unlike cool-season grass, whose roots also go dormant during the winter months as the temperature gets very cold, for the warm-season grasses, only the top goes dormant while the root remains active. Therefore warm-season grasses will benefit from light, infrequent watering during the dormant months.
Lawn dormancy is a natural state for grasses for survival. Therefore you don’t need to do anything to fix it. Maintaining healthy lawns before the dormant season and the right irrigation pattern during the dormant months will make your grass survive the unfavorable conditions.
Nitrogen deficiency can lead the grass to turn yellow as it is an important nutrient that makes the grass look green and healthy. But you should know that excess nitrogen can also make your grass turn yellow due to chemical burn and eventually kill it.
The best way to avoid this is to know the nitrogen levels of your grass. Send a soil sample to your local county extension office, and the laboratory test will reveal your soil’s nutrient composition. This will help you purchase fertilizer with the right nitrogen proportion for your soil, preventing you from overfertilizing it.
When you fertilize your lawn, it is essential to make sure that the fertilizer is distributed evenly across the entire area. You can use a seed spreader for this and slowly move across your lawn as you would do while mowing. When you make turns, do so carefully, as this is the region where most lawn owners drop more fertilizer than necessary.
To prevent chemical burns that are mostly caused by the use of synthetic fertilizers, you can use slow-release organic fertilizers, as they are gentle on your grass and provide it with the right amount of nitrogen over a prolonged period.
If you notice your grass turning yellow after fertilizing the soil, this is an indication of excess nitrogen. One way to repair this is to flush out the excess salts by watering the area deeply for four to seven days. This will make the salts seep through to the soil below the root zone of the grass. After this, you can lightly fertilize the area with the correct fertilizer composition to fix the loss of any other nutrients. This will slowly turn your grass green again.
If your grass does not turn green even after two weeks of deep watering, it means that the patch of grass is dead. Rake the area and till the soil to overturn the topsoil, and then reseed this patch or use sod. Irrigate and fertilize this area as you would a new lawn so that it grows healthy.
Another reason for your grass to turn yellow is soil compaction. Heavy foot traffic and the same lawn mowing patterns every time can cause the soil in these frequently used areas to become hard and compact.
Soil compaction leads the pores in the soil to squeeze together and prevents water, oxygen and significant nutrients from reaching the grassroots. This also does not allow the roots of the grass enough room to penetrate deeper into the soil, resulting in a shallow root system and thinning and discoloration of the grass.
If you want to know if your soil has become compact, these tips might help you:
- Take a soil sample. If it is hard and gray, that means your soil is compacted.
- Certain patches of your lawn start losing their density and thinning.
- Formation of puddles in the low areas of the lawn.
To fix soil compaction issues, you need to aerate the soil. To do this, you will need a core aerator, which is a tool with tines that mechanically pull out plugs or cores of soil, thatch and grass to loosen the soil. It is best to aerate the soil when it is moist. If you don’t own a core aerator, you can rent one from your local home improvement center or use a rake with metal tines for this purpose.
After the cores have been removed, rework the soil around these holes to loosen the soil and fill in the holes. Reseed all these patches with a grass type that complements your existing turfgrass and is suitable for your climatic conditions.
Fertilize the soil with compost and irrigate it regularly to keep the soil moist for the healthy germination of seeds. Once the seeds sprout, you can irrigate them according to the requirements of your lawn.
Edenapp suggests installing walkways or stepping stones to provide proper paths for navigating your landscape and reducing foot traffic on your grass.
Lawn diseases that cause the grass to turn yellow are mostly fungal diseases. Your lawn becomes prone to fungal diseases due to moisture levels (excessive rain), thatch and temperature conditions (frost burns). Some of the common fungal diseases that result in the yellow coloring of grass are:
- Dollar Spot
- Snow Mold
- Fairy Rings
The best way to prevent fungal diseases in your lawn is regular maintenance. Frequent dethatching of your lawn will prevent thatch buildup that holds water under your soil’s surface, preventing it from seeping deeper and getting absorbed.
To prevent fungal diseases like snow mold due to the winter temperatures, you should thoroughly dethatch your lawn before the season begins. Rake all the leaves and remove any kind of debris from your lawn before the first snowfall so that the moisture does not get trapped beneath these when the snow starts melting.
Aeration and overseeding are also recommended by Edenapp to maintain the health of your landscape as these processes ensure proper air, water and nutrient circulation in the soil and prevent the grass from thinning out. A healthy lawn has a greater tolerance for diseases.
If the fungal disease has spread to a large area of your lawn, fungicides can be applied to control it and prevent further damage. Different diseases might require different fungicides with specific combinations. Therefore, Edenapp recommends consulting a lawn care professional before the application of fungicides.
Too much or too little water
The right amount of water is required to keep your lawn looking green and healthy. Too little water will cause drought-like conditions and heat stress on your grass. This will cause your grass to dehydrate, resulting in loss of color and damage. To check if your lawn has dried out due to lack of moisture, try pulling the grass up. If the blades of your grass come out, then it means you have a dry lawn.
Another problem in regard to irrigating your lawn is overwatering it. Too much water in the soil causes your grass to develop a shallow root system, which leads to poor absorption of nutrients from the soil. Over irrigation also causes waterlogging; hence the roots will absorb limited oxygen. All of these factors contribute to grass that is weak and more susceptible to fungal diseases and pest infestation.
The correct irrigation amount for a lawn depends on the grass type, soil composition, and the temperature and climatic conditions in your region. But the average amount of water that established lawns require is about 1.5 inches per week.
Edenapp recommends irrigating your lawns in the morning to allow the excess water to evaporate due to the sun’s heat throughout the day. Also, deeply watering your lawn about once a week is recommended over frequent light watering throughout the week as this encourages the development of a deeper root system for your grass, leading to a healthy lawn.
Misuse of Chemicals
Sometimes, yellow grass is the result of a homeowner’s mishandling of chemicals. Chemical products like weed killers, fungicides, pesticides, fertilizers, etc., should be handled with care so that they do not spill on your lawn and damage patches of grass.
While applying these chemical products, you should carefully read the instructions on the product label and utilize only the recommended amounts to prevent chemical burn.
In case you spill chemicals on your grass by mistake, you should act promptly to minimize the damage. Grab some highly absorbent material like sawdust, calcined clay or even kitty litter to soak up the excess liquid on the surface. You can then dispose of this material by wrapping it in plastic and putting it with your non-biodegradable or toxic waste.
Don’t try to flush out the chemicals with water, as this will only spread it to the nearby areas of your lawn. Instead, dig out the contaminated soil according to the depth to which the chemicals have seeped through.
Fill this hole with weed-free topsoil and reseed the area. Fertilize and irrigate as required for healthy growth.
While fall colors are pretty to look at, leaving the autumn leaves on your grass for too long can cause the grass to turn yellow. This is because the leaves cover the grass and block the sunlight from reaching it, not allowing for proper photosynthesis. This causes the grass to grow weak and lose its color.
If the fall leaves are left on the lawn when it rains, the dry leaves will soak up the water and weigh on the grass, thus trapping moisture under them. Excess moisture is an invitation for fungal diseases.
These autumn leaves also provide a breeding ground for pests and insects that can be harmful to your lawn. Therefore, you should rake these leaves off your lawn to allow sunlight to reach the grass, prevent diseases and pests and keep the grass looking healthy and green. Raking the leaves as a routine will also make your yard look well-kept.
However, you don’t need to start raking the leaves as soon as they fall, as small numbers of fallen leaves break down fast and provide nutrients to the soil. Though, you should not let the leaves cover more than twenty percent of your lawn area, or your grass will start turning yellow. Rake the fallen leaves when they grow in number and use them for backyard composting.
Another culprit turning your lawn grass yellow could be thatch. Thatch is a layer of living and dead organic matter that forms just below the top layer of soil. A thin layer of thatch is good for your lawn, as it prevents the germination of weed seeds and retains soil moisture. But a thick layer of thatch (more than ½ inch) prevents air and water from penetrating the soil, leading the grass to develop a shallow root system. Small roots cause the grass to dehydrate quickly and thus lose color.
Thatch also prevents the proper flow of nutrients in the soil, making the grass turn yellow and lose its color due to nutrient deficiency.
To check if you have a thatch problem, dig out a small lump of soil. If you see a tan, intertwining layer of stems, grass blades and other organic matter, that is your thatch layer. Measure the thickness of the layer with a ruler. If the layer is half an inch thick or more, you need to remove thatch from your lawn because this is making your grass turn yellow.
You can remove thatch by using a dethatching rake. Before doing this, you should mow your lawn shorter than usual to expose the soil surface better. Pass the dethatching rake or any other lawn rake with sharp metal tines over the surface of the soil to break up the thatch. After this, you can rake up the thatch and any other debris to dispose of them.
You can slow down thatch accumulation by mowing your grass to the recommended height according to its type and following the one-third rule of cutting grass. Edenapp also recommends infrequent deeper irrigation compared to frequent light irrigation and occasional top dressing to prevent fast thatch accumulation.
How to Turn Yellow Grass Green Fast
Once you have figured out the cause of your lawn grass turning yellow, you should take the right measures to control the problem so that your grass can regain its vigor and withstand pests and diseases while looking green and healthy again. Here are some methods suggested by Edenapp to turn your yellow grass green again:
- Reseeding Urine Stains
- Make Changes to Your Irrigation Schedule
- Apply Fertilizer to Your Lawn as Needed
- Identify and Treat Lawn Diseases
- Sharper Blades Should be Used for Mowing
Reseeding Urine Stains
The grass on the dog urine spots will not turn back yellow to green if your dog has been peeing in that spot for a prolonged period. Therefore, keeping an eye on your pet is important. When your dog goes out to do its business, follow it and apply a dog urine neutralizer to the spot immediately after.
If the grass stays yellow after multiple applications of the neutralizer, then that means that the grass has died due to the excess nitrogen present in the dog’s urine. In this case, you need to reseed or re-sod the soil in that area.
For reseeding, you need to first cut the grass shorter than usual. Then use a rake to clear out the debris and overturn the soil. If there is a lot of thatch present, you need to dethatch the soil with a dethatching rake. Once the soil is exposed, you can spread the seed over the area by hand or use a seed spreader if the area is more extensive. Choose the grass seed that will complement the existing grass on your lawn and survive in your climatic conditions.
After spreading the seed, you can apply a thin layer of enriched topsoil on the seeds to provide them with enough soil exposure. This is optional. After this, irrigate the area lightly and frequently enough to keep the soil moist at all times, especially during the first week. Then you can make your irrigation pattern more infrequent but deeper to promote a more in-depth root system.
Make Changes to Your Irrigation Schedule
Irrigate your lawn only when required. For example, if rain is forecasted for the day, you should probably avoid watering your lawn because you will be overwatering your lawn in this case. Also, different types of soil composition have different irrigation requirements. Soil with higher clay composition will require less water, as clay holds water well. On the other hand, soil with higher sand content will require more water as sand makes the water drain very quickly.
Here are some helpful tips for irrigating your lawn:
- Know your grass type: This will allow you to determine the right amount of water for your lawn, as different grass types have different irrigation requirements. Here are some water guidelines for different types of grass per week:
- Bermuda Grass: 1¼ inches
- Perennial Ryegrass: 6 inches
- Zoysia: 1 inch
- St. Augustine Grass: 1 inch
- Buffalograss: 0.3 inches
- Tall Fescue: 0.8 inches
Kentucky Bluegrass: 1.2 inches
- Water deeply about once a week instead of shallow irrigation multiple times a week: This irrigation pattern allows your grass to develop a deeper root system, making them more resistant to unfavorable conditions.
- Irrigate when two inches of topsoil is dry: This is a good indication of when to water your lawn to prevent overwatering and under watering.
- Use a soil moisture probe: You could invest in a simple and inexpensive soil moisture probe to help you determine the moisture level of your soil and adjust your irrigation schedule accordingly.
Apply Fertilizer to Your Lawn as Needed
As much as one would like to feed their lawns to make sure their grass does not lack any nutrients, it is also essential to be careful about overfertilizing the lawn. To determine the right fertilizer composition for your soil type, Edenapp recommends doing a soil test. You could consult your local county extension office or a professional landscaper for this. This laboratory test will not only reveal any nutritional deficiencies present in your soil, but also inform you on how to correct them.
According to the results, you can buy the correct fertilizer for your soil. Before application, you should read the application directions given on the product label carefully to avoid damaging your grass with chemical burns. While spreading synthetic fertilizers, you should make sure to distribute evenly across the entire area by using a broadcast spreader.
Edenapp recommends using organic fertilizers over chemical fertilizers as they are environmentally responsible and are better for the overall health of your landscape, even if they are a little slow to take effect.
Identify and Treat Lawn Diseases
Fungal diseases on lawns are caused due to a number of factors like excessive heat, humidity, compacted soil, overwatering, too much or wrong fertilizer or if your grass type is not suitable for your climatic conditions.
Some symptoms of fungal lawn diseases are:
- Yellow, brown or white patches of grass or rings
- Powdery or threadlike coatings on the grass blades
- Patches of darkened, wet and greasy-looking grass
- Brown or dead grass that is frayed and distorted
Fungal infections do not go away on their own and need to be treated immediately and thoroughly to avoid more damage. Fungal infections can be eradicated by following good landscaping practices and maintaining a healthy lawn. Given below are some of these practices:
- Do a soil test to identify nutrient deficiencies and correct them.
- Dethatch your soil to remove buildup and allow proper flow of air, water and nutrients.
- Aerate your soil every one or two years to loosen compacted soil.
- Choose the right grass type to plant in your yard according to your geographic location.
- Use organic products for your lawn, as synthetic ones can upset the ecological balance of your landscape.
- Follow the recommended mowing, fertilizing and irrigation practices
- If all of these fails, and you have to resort to using fungicides, identify the cause and the type of infection before applying the fungicide because not all fungicides are built the same.
Sharper Blades should be Used for Mowing
If the blades of your lawnmower have become dull, then they will hack, shred or rip the grass blades instead of cutting them cleanly. This causes a lot of stress on the grass blades, and therefore you will see the blades become yellow after every mowing.
To fix this, you need to keep the blades of your mower sharp at all times. How frequently you sharpen them depends on the area of your lawn and your mowing routine. Edenapp recommends sharpening your blades every time you finish three hours of mowing to achieve the best results.
Sharpening your mower blades regularly has environmental benefits as well. Gas-powered lawn mowers mow more efficiently with sharper blades. Less gas is used up in the process, which leads to fewer emissions.
When Should You Hire a Lawn Care Expert
As you can see, the causes of yellow grass are mostly irregular lawn maintenance or incorrect landscape practices. This is the reason why you should hire professional lawn care services to perform regular lawn maintenance tasks like mowing, dethatching, irrigation, fertilization, aeration, etc., in the correct manner. Maintaining a healthy lawn is key to making it more tolerant of conditions like drought and stress.
A professional landscaper will also perform regular inspections to ensure your lawn remains disease, pest and insect free.
Edenapp is a professional lawn care and landscaping service with specialists who boast experience and expertise in all aspects of lawn and landscape. You can trust us to maintain your lawn to the highest standards so that it can function at its best in all the seasons of the year. Contact us today to learn more about the services we offer.
Grass cutting taking up all your time? Call us, and we will do it for you!