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Why is My St Augustine Grass Turning Light Green? Causes & Solutions (2023)

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why is my st augustine grass turning light greenAre you tired of looking at your lawn and seeing light green grass instead of a lush, healthy St.

In order to figure out why your St. Augustine Grass is turning light green, we must first understand what causes the change in color and then look into solutions that will help restore its natural hue.

There are many explanations as to why your beloved turf may be exhibiting signs of discoloration. From root rot or nematode infestations to a lack of nutrients or too much shade – all these factors play a role in the healthiness (or unhealthiness) of your lawn’s appearance.

Let’s delve deep into some common causes and find easy steps you can take towards greener St.

Key Takeaways

  • St. Augustine grass can turn light green due to root rot, nematode infestations, lack of nutrients, and insufficient sunlight.
  • Fungicide treatment can help reduce the effects of root rot, but soil testing is necessary for confirmation.
  • Iron supplements may be needed to restore deep green coloration in St. Augustine grass affected by nutrient deficiencies.
  • Improving grass and soil health is crucial in addressing nematode infestations.

Your Grass is Suffering From Root Rot

why is my st augustine grass turning light green 1
You may be noticing patches of thinning, yellow or light green grass – a sign that your lawn is suffering from Take All Root Rot. This fungal disease causes discoloration and death in St. Augustine grass. Symptoms include pale color, wilting leaves, and bare spots across the entire lawn.

To reduce the effects of this root rot, fungicide treatment can be used, but soil testing should first confirm it as the cause for why my St. Augustine grass is turning light green. Additionally, iron supplements are sometimes needed to restore deep green coloration in St.

Augustine grass affected by nutrient deficiencies, such as nitrogen or iron deficiency due to sandy soils.

Lastly, adequate sunlight helps ensure lush, dark-colored turf. Trimming bushes near your lawn and considering shade-tolerant varieties might help address any lack of sun issues. Proper watering according to soil type (sandy versus clay) will go a long way towards preventing further damage from occurring on those areas already showing signs of distress caused by root rot infestation.

Your Lawn Has Nematodes

Your Lawn Has Nematodes
Nematodes can take up residence in your lawn, causing thinning and pale color. Soil testing is necessary to confirm if nematodes are the cause of why your St. Augustine grass is turning light green – there’s no chemical solution for eliminating them, so improving grass and soil health should be the first step taken when battling these pests.

Iron supplements may help restore deep green coloration due to nutrient deficiencies such as nitrogen or iron deficiency caused by sandy soils. Slow-release fertilizers will aid in restoring nutrients as well. Fungicide usage may also be needed if root rot has had a chance to set in prior to any other treatments being applied.

However, it’s important that soil testing confirms this before beginning fungicide treatment with anything else.

Water monitoring according to clay or sandy soil type will go a long way towards preventing further damage from occurring on those areas already showing signs of distress caused by infestation.

Your Grass is Lacking Nutrients

Your Grass is Lacking Nutrients
If nutrients are lacking, your lawn may need slow-release fertilizers to restore green color and replenish the soil. The best way to determine if this is the case is through soil testing, which will help you identify any nutrient deficiencies in your St.

Nitrogen and iron are essential for deep green coloration, so look out for signs of these deficiencies such as pale green or yellow patches on your turf.

Iron supplements may also be necessary depending on how severe an iron deficiency there is – again, soil testing should guide applications here too! Shade-tolerant varieties might help address lack of sunlight issues that could cause lightening of grass hue as well.

Finally, water monitoring according to clay or sandy type soils will ensure proper hydration levels remain consistent throughout those areas already showing distress from infestation – preventing further damage from occurring altogether if done correctly!

There is Not Enough Sunlight on Your Yard

There is Not Enough Sunlight on Your Yard
Transitioning from nutrients to the current topic, let’s focus on how sunlight may be impacting your St. Augustine grass turning light green. To ensure this isn’t the culprit, you’ll want to check for adequate sun exposure and trim any nearby bushes or trees that might be blocking out too much of it if needed.

If there are still patches of lighter color appearing even with increased access, consider applying a shade-tolerant variety in those areas as well!

Iron supplement applications should also be considered when soil testing reveals an iron deficiency is present – which could lead to pale green or yellow patches on turf blades due to lack thereof.

Finally, monitoring the water schedule according to either clay or sandy type soils will prevent future damage from occurring due to both infestation and improper hydration levels alike; so don’t forget about this important step in restoring lushness back into your lawn again soon enough!

Your Grass is Not Getting Enough Water

Your Grass is Not Getting Enough Water
To keep your lawn in its best condition, make sure you’re watering it according to the soil type and maintaining a proper hydration schedule. Sandy soils need more frequent waterings than clay ones. This not only promotes healthy growth of St.

Augustine grass but also prevents the formation of light green or yellow patches due to insufficient moisture levels.

Consider applying iron supplements if testing reveals an iron deficiency. Slow-release fertilizers can help restore deep green coloration to your turf blades as well. Additionally, in areas that don’t receive enough sun exposure, applying shade-tolerant varieties can help with any issues of discoloration caused by lack of sunlight.

Improving soil health overall is key to keeping St. Augustine grass vibrant and lush throughout the year. So don’t overlook this important step when trying to find out why your grass may have turned lighter shades recently.

What Makes St. Augustine Grass Turn Light Green?

What Makes St. Augustine Grass Turn Light Green?
If your St. Augustine grass has recently turned light green, there could be multiple causes. Take All Root Rot is a disease that can cause yellow or light green patches in the lawn and requires fungicide to lessen its effects.

Nematodes are another common issue with this kind of grass, which may require soil testing for confirmation. However, no chemical solution exists for eliminating them, so improving overall turf health is key.

Additionally, lack of nutrients or too much shade might also be contributing factors leading to discoloration and thinning in St. Augustine grass. Both of these issues can be addressed by applying slow-release fertilizers and considering shade-tolerant varieties, respectively.

Take All Root Rot

Be aware that Take All Root Rot can cause St. Augustine grass to yellow and thin, so diagnose your turf with a soil test if you spot signs of the disease. Fungicide application helps reduce root rot symptoms, but proper prevention is key for long-term success.

Iron supplements may be needed for nutrient deficiencies, while shade-tolerant varieties are good options when sunlight is limited.


Soil testing and iron supplements can help restore lush color to your lawn. Proper care prevents future light green patches, while fungicide application addresses Take All Root Rot. Sandy soils require slow-release nitrogen fertilizers for deep greens, and clay soils need regular watering.


Nematodes are a common cause of lawn discoloration, but no chemical solution will eliminate them. The best approach to restoring vibrant greens is improving grass and soil health.

  • Use fungicide for Take All Root Rot
  • Consider shade-tolerant varieties
  • Complete soil testing to identify iron deficiency
  • Fertilize with nutrient-rich fertilizers. Regular waterings and proper maintenance can keep your St. Augustine grass healthy and green all season!

Lack of Nutrients

To maintain lushness and deep-green color in your lawn, regular soil testing is essential to identify nutrient deficiencies that could be causing discoloration. Iron deficiency, an imbalance of nutrients, or improper water management can all lead to St.

Too Much Shade

Too much shade can leave your lush green lawn looking pale and lifeless. To prevent this, ensure proper irrigation; improve soil drainage; use proper mowing, fertilizing, and soil aeration techniques. Uncovering underlying issues such as too much shade requires a keen eye for detail to identify potential problems before they arise.

Easy Steps for Greener St. Augustine Grass!

Easy Steps for Greener St. Augustine Grass!
Are you wondering why your St. Augustine grass is turning light green? Look no further for the solution! With a few simple steps, including using slow-release fertilizer, getting plenty of sunlight, and applying the right amount of water to your lawn, you can restore its deep green color in no time.

Slow-release Fertilizer

Applying slow-release fertilizers is an effective way to restore the deep green color of your lawn and address any nutrient deficiencies. Nitrogen-rich fertilizers can help St. Augustine grass suffering from sandy soil or iron deficiency, while shade-tolerant varieties should be considered for areas with insufficient sunlight.

Lots of Sun

Getting plenty of sunlight is essential for keeping your St. Augustine grass looking its best. The Smith family, for example, had to trim their trees and shrubs to let in more sun. This quickly restored the deep green color of their lawn! However, be careful not to over-expose your grass to too much light, as it can cause sunburn.

Adjust your watering habits based on whether you have sandy or clay soil. When it comes to fertilizing, consider using slow-release nitrogen-rich formulations, iron supplements, and shade-tolerant varieties for shady areas.

The Right Amount of Water

You need to water your St. Augustine grass regularly and correctly for it to stay lush and green! Here are some tips:

  1. Watering frequency should depend on soil type; sandy soils require more frequent watering than clay soils.
  2. Supplement your lawn with iron, a nutrient key in keeping the grass healthy and deep-green colored.
  3. Use slow-release nitrogen-rich fertilizers which will sustainably provide nutrition over time without burning or leaching away from the roots of the grass blades too quickly like synthetic fertilizer can do.
  4. Water deeply but not often; this encourages root growth leading to better drought tolerance in dry spells as well as helps keep weeds at bay due to injury when competing against established turf roots for moisture resources during extended periods of hot weather conditions!

With these steps, you can maintain beautiful, bright green St. Augustine Grass year-round!

Frequently Asked Questions (FAQs)

Is St. Augustine grass good for sandy soils?

Yes, St. Augustine grass is ideal for sandy soils due to its ability to thrive in low-nutrient conditions. Its dark green color and lush texture make it a popular choice for warm coastal areas of the southeastern United States.

Is there a chemical solution to eliminate nematodes?

No, there is no chemical solution to eliminate nematodes. The most effective way to deal with them is by improving the health of your soil and grass.

What are the best slow-release, nitrogen-rich fertilizers for St. Augustine grass?

Try slow-release fertilizers like Milorganite, Scotts Turf Builder, or Pennington Smart Seed. These products provide nitrogen to your St. Augustine grass for a deep green color and vigor.

What are some shade-tolerant grasses that can replace St. Augustine grass?

Shade-tolerant grasses that can replace St. Augustine include zoysia, bermudagrass, and centipede grass. All are low maintenance and have a deep green color when given enough sunlight and water.

What are the watering requirements for St. Augustine grass in both sandy and clay soils?

Watering requirements for St. Augustine grass depend on soil type: sandy soils need frequent, shallow waterings, while clay soils require deep, infrequent sprinkles.


You can have a lush green lawn if you take the right steps towards maintaining St. Augustine grass. Root rot can be treated with fungicide, and nematode infestation can be addressed by improving the health of the grass and soil.

Make sure your grass is getting the right nutrients, plenty of sunlight, and the right amount of water for your soil type. It may seem like a tall order, but with a little TLC, you can be sure to have a lawn that’s the envy of your neighbors.

So don’t waste another minute – it’s time to get your green thumb into gear and start taking care of your St.

Avatar for Mutasim Sweileh

Mutasim Sweileh

Mutasim is a published author and software engineer and agriculture expert from the US. To date, he has helped thousands of people make their yards lush and thick.