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What’s the Difference Between Chelated and Non Chelated Iron for Lawns?

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Written By: Mark Marino

a Massachusetts Core Applicator License holder and owner/operator of Lawn Phix,

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If you’re longing for a lush vibrant green lawn but yours remains a dull or pale green, your soil might be iron deficient–or it might have a high pH that makes it difficult for the plant to use existing iron in the soil. Fortunately, iron deficiencies are not difficult to correct when you take the time to get to know your soil’s needs. Many people don’t worry about iron because soil fertilizers tend to focus on nitrogen, phosphorus, and potassium, but iron is essential too. Iron supports chlorophyll production in the plant. Your grass will struggle to produce chlorophyll if it’s iron deficient. The following article explains which iron supplements to choose and how they can enhance your lawn. 

What’s the Difference Between Chelate and Non-Chelated Iron?

Some gardeners are stumped by this scenario: there’s iron in their soil but their lawn isn’t greening up as it should. What’s going on? 

Simply put, non-chelated iron is plain old iron. Chelated iron refers to chelate molecules that protect the iron, preventing it from turning to rust, and allowing it to be absorbed by plants such as your cool-season grass. 

In some situations, there may certainly be ample iron in the soil, but if the pH of the soil is high, the plant may not be able to absorb the iron. When iron comes into contact with oxygen or hydroxide (found in water), it can’t be used by the plant. Chelated iron, on the other hand, can be. 

Iron is a common nutrient found in soils. As mentioned, plants need it for chlorophyll production. Chelated iron, conversely, is iron that’s chemically protected by chelators. Air and water render the iron in soil useless to plants, but chelators protect the iron, keeping in the form that plants can use. If your plant doesn’t get the iron it needs, it will appear pale and may even suffer from a condition known as iron chlorosis, which is essentially an iron deficiency in a plant. The plant’s veins may be more visible, its coloring pale green to yellow, and its foliage edges brown.

You might suppose it’s best to always use chelated iron like a chelated liquid iron spray when fertilizing your lawn. Of course, you can also suppose that chelated iron fertilizers will be more costly than simply adding iron as needed to your soil. Your lawn may not need chelated fertilizer, especially if it has a low pH. It’s acidic oil that tends to make it difficult for grass to absorb iron. If you have a high soil pH, you might then opt for chelated iron to correct an iron deficiency in your lawn. 

What Causes Iron Deficiency in Lawns?

There are a few reasons why your lawn might have an iron deficiency. One of the most common is that the soil pH is too high. High soil pH makes it difficult for grass to absorb iron. In these situations, chelated iron is the ideal solution. Iron deficiency in lawns can also be due to overwatering. Water causes oxidation in the iron, which makes it unusable for plants. Of course, there’s always the possibility that the soil pH is just right but that the soil simply doesn’t contain enough iron to meet the lawn’s needs. You can correct iron deficiency by adding iron to the soil. Chelated liquid iron spray or chelated granular iron may not be necessary in this case. 

Why Is Chelated Fertilizer Needed?

Chelated fertilizer refers to the addition of chelators that protect the iron. The chelators aren’t all the same. Some protect the iron for a longer period of time than others. Once the chelators begin to fail, the iron can become oxidized and no longer useful for the plant. To guard against iron chlorosis or iron deficiency in your soil, you might want to use chelated liquid iron fertilizer or granules to ensure that your lawn has plenty of usable iron. 

Types of Chelated Iron for Lawns

If you decide to fertilize your lawn with chelated fertilizer, you have several options. FerromecAC is one of our favorite options because it reliably greens up a pale lawn and is known for its long-term stability. That’s important because you don’t want to have to worry about correcting an iron deficiency perpetually. With long-lasting chelators added to the formula, the iron will remain usable for plants, supporting their healthy chlorophyll production. 

Favorite product aside, here are the four most common iron chelators lawn care experts at Michigan State University used today:

Citric Acid

Citric acid does not form an especially strong bond with iron to provide long-lasting protection against oxidation. Also, it’s not effective for use as a chelator in soils with a soil pH of above 6.0.


EDTA forms a strong bond, but not beyond soil with a pH of 6.5. 


Generally preferred to the other former two, DTPA forms a strong bond with iron and provides protection in soils up to a pH of 7.0.


EDDHA is the strongest of the commonly used chelates, ensuring that plants can absorb the iron even in soils that register a pH as high or higher than 9.0.

When choosing chelated iron, remember that if you’re choosing a foliar spray, the chelators aren’t needed. You’ll find chelated foliar spray but it’s more expensive and simply isn’t required. If you are correcting iron deficiencies in the soil, you may want to use chelated iron, especially if your soil pH is on the high side. You can purchase chelated liquid iron fertilizer at your area garden center or home improvement centers in most cases. You can also find liquid iron products online.

Chelated and Non-Chelated Iron FAQs

How to use chelated iron?

When purchasing chelated iron for your lawn, you’ll want to use the liquid iron on granular iron supplements as directed on the product. Be sure to add iron to your lawn when temperatures range between 40 and 8 degrees. Spring is the best time to add iron to an iron-deficient lawn.

What does iron do for lawns?

Iron supports the lawn’s ability to produce chlorophyll, the compound that gives it its deep green color. If your lawn is pale green or yellowing, it might benefit from an iron supplement. A chelated iron supplement may be needed if your soil has a high pH.

What is the benefit of chelated iron?

Chelators bind to iron molecules and protect them from the effects of oxidation–which are inevitable as the iron comes into contact with air or water. Once oxidation occurs, the plant can’t absorb the iron. The chelators protect the iron so that it remains usable by plants like your lawn.

What does chelated iron mean?

Chelated iron means that the iron has been formulated to include the addition of chelators. These chelates molecules protect the iron so that it can remain in a usable for for plants like grass. Chelated iron is ideal for correcting iron deficiencies in soil.

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Author's Note: this piece has been updated for accuracy since its first publication on
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Author: Mark Marino
My name is Mark Marino, and I am the founder, owner, and operator of Lawn Phix. With a passion for lawn care and turf nutrition for over a decade, I've dedicated countless hours to correcting soil and perfecting lawns. Today, my expertise, backed by formal courses at UMass Extension Pesticide Education, allows me to offer top-tier lawn care services and advice. I am a fully licensed and insured lawn care applicator in Massachusetts, specializing in comprehensive turf nutrition, weed control, and lawn pest control. My license number is AL-0053865. Contact me at [email protected] or +1 (508) 500-8402.

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