10 Reasons Your Grass Is Yellow…Or Is It Dead?


I had just finished mowing my lawn yesterday and I started to see blotches of yellow grass everywhere. My neighbor mentioned that he is having the same problem so I decided to do a little research to find the solution for both of us.

Grass turns yellow due to a lack of nutrients, diseases, insects, improper fertilization, or other external factors. External factors include changing temperature, pH of the soil, and improper amounts of sunlight leading to a lack of ability to properly process the nutrients it does have.

There is a bit more that goes into diagnosing why your grass is turning yellow. Below we will go more in depth as well as find out if there is anything we can do or if it is already too late to save this batch of grass.

Reasons Your Grass Is Dying

Here is a quick reference list of the possible causes your grass is dying.

  1. Improper Mowing
  2. Lack of Fertilization
  3. Nitrogen and Iron Deficiencies
  4. Insufficient Water
  5. Too Much Water
  6. Seasonal Grass Type
  7. Harmful Chemicals
  8. Not Enough Sunlight
  9. Grass Diseases
  10. Pests

Read on below to find out in a little more detail and we can talk a little more about why your grass is yellowing before discussing the solutions to your problems.

  1. Improper Mowing. There are certain practices when mowing the lawn that could lead to your grass of essential elements. Cutting your grass more than 1/3s of the original height can expose the grass sheathes which takes away the growing green top of the blades as well as possible allowing hot summer sun to scorch to roots. This causes excessive plant stress as the green leaf blade is responsible for the majority of photosynthesis restoring the plants crucial stores.
  • Also, if you wait to long to cut your grass it leads to large grass clippings(thatch) that can restrict the amount of light to your grass and does not provide the same nitrogen value that small clippings do to the growing grass.
  1. Lack of Fertilization. Your grass may be suffering from a nitrogen deficiency. If your grass is becoming slightly greener and then turning yellow it might be time to add some slow release fertilizer. Often times this is required in the fall or spring but can change based off of your type of grass and climate.
  1. Nitrogen and Iron deficiencies can also cause yellowing grass. This can be mitigated using the small grass clippings for nitrogen and plant food contains both nitrogen and the iron that your soil needs replenished.
  1. Insufficient Water. During periods of little rain your lawn may need a supplement of water. To little water or and uneven lawn that is only giving water the lower spots in the lawn can cause yellow patches across your lawn. If the top 1 or 2 inches of your soil is dry than you should consider applying water once or twice a week depending on your rainfall.
  • Timing of watering is also important as you should water in the morning to allow time for the grass to dry before the heat of the day which if not done can burn the grass roots.
  1. Too Much Water. Yes I know if feel contradictory, but pooling water can rot the roots of the grass or be a welcome environment for any number of fungi or disease. Using proper drainage can be the solution you seek and can if you want to know more about how it works, here is a helpful article that explains it.
  1. Seasonal Grass Type. Yes, your grass may be getting too cold or too hot. The good things is there are numerous types of grass that do perfectly fine together and seeding your cool season grass with some warm season grass can benefit both as one will thrive while the other becomes dormant during its off season.
  1. Harmful Chemicals. Not the kind you will find in a glass beaker in a chemistry lab, but the ones you will find coming out of the insect killer, tiki torches, lawnmower gas tank, or your pet. All of these things change the pH of the soil and can cause localized patches of yellowed grass because it is taking away the grasses ability to process the nutrients in the earth.
  1. Not Enough Sunlight. If you just have a ton of trees in your lawn your grass may not be getting enough sunlight. Thinning the number of trees in your lawn or pruning limbs in some key locations could be just the trick you need to provide just enough sunlight to your grass.
  1. Grass Diseases. Smut, Snow mold, smut, and fairy wings are some of the most common grass diseases. These can all be combated with a fungicide and good general lawn care practices that will strengthen your lawn in its fight against disease.
  1. Pests. To identify if this is the true issue use a magnifying glass to see up close on the blades. Part some of them to get a better look. There is a significant number of possible grass eaters and identifying them young so you can kill them when they are larva is critical in saving you from the hurt locker. Using an insecticide for that pest should get you ahead of the problem.

If you have these pests that dig up your lawn identify them quickly before the damage to your lawn is irreversible. If you need help identifying what type of pest you have or what to do about it we wrote and article to help.

  • Another type of pest is other plants. Look at your lawn and determine if this is all actually grass. Sometimes those pretty little lawn flowers are actually slowly taking over killing off the grass around them because they have deeper roots and grow faster.

One of the worst plant pests you can have is moss, we wrote about it here to help you remove that unwanted moss taking the critical nutrients from your grass.

How To Revive Your Grass

We have already talked a little about the solutions, but summarizing good lawn practices that will take care of your lawn regardless of what the issue is will prevent these issues before they even arise.

Watering Schedules can easily solve the problem of too frequent or infrequent rain. If you have a rain in the first half and second half of the week then you are probably good. If not, just ensure that you turn on that sprinkler system at least once during the dry spells.

Also, spraying down areas where your pet just went to the bathroom or abnormal chemicals just fell. Sometimes it is required to just replace that spot of dirt and replant seed to provide the growth you are looking for.

Arrangement Issues of the plants or components of your yard could be cause. For this, thinning out or pruning your trees could be a good first step allowing plenty of sunlight in.

Areas near a deck, patio, pool, shed, or other structures could very well be changing the pH of the soil around it and could require more frequent fertilizing. Planning on fertilizing your lawn twice a year, depending on what type of grass you have can prevent this heartache.

Drainage is a big issue for a lot of properties and it can develop later on in the life of your property due to construction, erosion, or other unforeseen factors. There are many reasons to consider the different drainage options. Some can be expensive, but there are definitely cost effective ways to keep a healthy lawn.

If you need help identifying which drainage system is best for you than check out this article where we discuss the pros and cons of each.

Proper Mowing. Really just follow these simple things:

  • Don’t wait till its too long to mow
  • Don’t cut it too short(Just 1/3 of its length)
  • Allowing small clippings to remain replenishes nitrogen
  • Remove large clippings(thatch), they deprive the grass of light

If you don’t remove those larger clippings it can create a huge headache for you later when it compacts itself later. We talk about it here as well as how to avoid/fix it if it happens.

Just like that a mowing schedule was born. Your type of grass may change this, but cutting your grass every 1 to 2 weeks during the warmer months and every 3 to 4 weeks during the cooler months is a pretty good thumb-rule to follow.

Fertilization can go a long way to giving your grass what it need on a consistent basis to continue to grow. Every 6 months or so is a good baseline to follow. If you want to go longer or shorter than consult a professional. Your lawn may be naturally fertilizing itself depending on the amount of natural plant decomposition going on.

Aerating your lawn prior to any fertilization helps drive the nutrients deep to where the roots are and replenish the ground that the grass grows from.

Is Your Grass Dead Or Dormant?

Quickly lets talk dead grass. If you think all is lost than you may be right, but for your lawns sake I hope your not and below are some tricks to finding out if you are right.

Dormant grass may be considered to be on life support. It is conserving all of its energy and maintaining all of its resources to the roots and crown of the grass to stay alive for as long as possible. Your grass can stay in this state for about a month before it starts to kick the can. I’ll put it this way, if you are noticing this now it means you have little under a month to start giving your grass what it needs before you end up with a brown wasteland.

Dead grass looks almost the same, which leads you to ask “How can I tell then?!” Hold tight cause there are some ways.

Tug on the grass. If it is difficult to pull out it means the root system is alive and healthy enough to fight back, where as if it just comes right out you probably have a bit of decaying plant matter in your hand and could probably compost it for all of the grass seed you are about to plant.

Bottom line if your grass has uniformly turned brown or yellow and there are no obvious signs than it is probably dormant. A patch of brown grass is rarely randomly dormant and is likely some other issue. Do not fret though, with a little planning and some seed you can have a healthy lawn in a few months time.

Manny Moore

Getting my hands dirty and building a place that me and my small family love is a driving factor for what I do and how I do it. I want to share what I have learned and practiced so that it is just that much easier for everyone to have another tool in their tool belt. Your home should be a place that you love and feel comfortable in and your backyard should be no different.

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