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Wednesday, 17 March 2021
Why is my grass turning yellow?

Why is my grass turning yellow?

Many people take pride in how beautiful their gardens are, which is why it’s quite disheartening when yellow spots appear on your lawn. Thankfully, there are reasons and solutions for this. 


Why is my grass yellow?

The lawn is lacking the required nutrients

This is, by far, the most common cause of yellowing lawns. A lack of nutrients in the soil is unhealthy for the lawn and makes it susceptible to pest infestation and disease. Iron deficiencies are typically the cause of yellow spots, especially in spring. 

This occurs when plant or organic matter with a high carbon content is added to the soil. Also, organisms take nitrogen from the soil to break down carbon which can result in nitrogen deficiencies if the nutrients aren't replenished.

A lawn expert can test the soil to see its composition and chemical levels to determine what deficiency is affecting your grass.


You can never have too much of a good thing, right? Unfortunately, plants can, and overwatering can lead to yellowing. 

Unlike soil composition, overwatering is easier to investigate. If your grass squishes and squelches a few hours after watering, then you may have an irrigation or overwatering issue. You may also notice the rapid emergence of weeds or lawn fungi which will grow in overwatered areas.


Over a couple of hot days, your grass can become scorched and burnt to a crisp. In this case, because the roots aren’t damaged by the sun or heat, it means the grass is still alive under its yellow skin. If you wait till the heatwave is over and gradually water the grass, it will recover.

A good tip to water during the summer or a heatwave is to avoid using sprinklers. Sprinklers only water to a shallow level which will gradually evaporate. In this case, the water needs to reach the deeper roots at about 10 cm below the surface level.

Lawn Mowers

Lawn mowers can affect the grass in two prominent ways:

  • Blades of grass hold nutrients and moisture which is why when you cut the grass too short, it will turn yellow. If this continuously happens, you should adjust the blade height on your lawn mower to ensure enough grass is left to hold enough nutrients and water to grow.
  • Lawn mower gasoline spills can damage and kill the grass. When filling up the lawn mower, be sure to do it away from the grass and dilute it with water to avoid contaminating the soil.

Outdoor equipment

Lawn care is a science so understanding the soil and the components it needs for growth will help you determine what can and cannot kill the grass. Children or outdoor equipment (swings, trampolines, BBQ equipment, dog houses, etc.) that are placed on the grass will cause the close surrounding patches to turn yellow due to soil compaction.


Should I leave grass clippings on the lawn?

There is no harm in leaving your cut grass on your lawn. As the grass decays and breaks down, the nutrients will penetrate the soil and fertilize it. This means you do not need to spend money on chemical fertilizers!


Is my grass dormant or dead?

Grass can be very deceptive. Fortunately, there are some tests you can perform to see if your grass is dead or simply dormant.

Believe it or not, one of the simplest ways to check is to tug on it! If you tug on the yellowing grass and it pulls out with little resistance, then it is probably dead.

Dormant grass still has strong, growing roots. So, if you tug and there is some resistance, then there is hope.

You should also know that different species of grass lay dormant during certain weather or at different times of the year.

Cool-season grass, which prefers cooler temperatures, will lay dormant when it's hot in order to survive. As for warm-season grass, it will lay dormant in cooler temperatures. 


Can dead grass kill other grass?

Dead grass will not kill your other grass unless it develops into what is called ‘Thatch’. Thatch happens when dead grass collects and combines with roots, dry soil, and other matter.

When the decaying grass begins to compact and form thatch, it suffocates and reduces the airflow to the surrounding grass. Thatch can also become a breeding ground for pests like mosquitos, and fungus.


Can yellow grass recover?

YES! By understanding the science and reasons why yellowing occurs, you will be able to fix and treat the yellowing with straightforward strategies. In an ideal situation with quality soil, good weather, and well watered and cared for grass, it may take just a week to recover it. In other cases, you may need the help of a lawn maintenance expert


How to stop lawn grass from turning yellow?

There are multiple causes which can destroy your lawn, but don’t worry as there are also multiple lawn care solutions to help rejuvenate growth!

  • If your grass yellows during a heatwave, water it at a deep level in the evening to avoid evaporation. To get 10 cm below the surface level, use a peg, pencil, or screwdriver to poke holes in the dirt. This will allow the roots to soak up the water. Keep in mind, however, what kind of soil you have as you do not want to overwater it! 
  • If your grass yellows because of lack of nutrients, add fertilizer. You contact a company to do soil testing. The results will tell you what nutrients the soil needs!


Lawn practices to prevent yellow grass

  • Identify places where water can accumulate and fill it in with absorbent materials such as dirt or sand. This will reduce the chance of disease breeding.
  • Drainage and irrigation are key to a healthy lawn. A professional landscaping company can assist you with identifying areas needed for improved drainage.
  • Use the right grass! Many of us will plant cool-season grass in a warm location. Be sure to plant grass and turf that is right for your region’s climate.
  • Routinely check for soil deficiencies and add fertilizer accordingly.
  • Increase the blade height on your lawn mower.
  • Only mow when your grass is dry.
  • Make small holes at intervals to ease water and airflow into the soil.


Need help to turn your grass green? 

Eagleyard is a lawn care company with over 30 years of experience. We offer lawn care packages to ensure your peace of mind. If you’re worried about your lawn and need assistance, don’t hesitate to contact us.