Can Too Much Iron Hurt Your Lawn?

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The best way to achieve a green and well-manicured lawn is to ensure that the grass gets the desired nutrients. 

One of the important nutrients responsible for aiding grass growth is iron. But the big question is, can too much iron hurt your lawn?

Let’s find out!

Can Too Much Iron Hurt Your Lawn?

Iron boosts growth and makes your lawn look green and lush. Ironite is one of the important iron supplements used for grass.

It contains high levels of nutrients to ensure a healthy-looking lawn. Before we discuss the effects of excessive application of iron on lawns, let’s take a quick look at the importance of this mineral:

  • Your grass might appear vulnerable to disease during the winter and autumn months, applying good liquid iron for your lawns will enhance its resistance to diseases to make your lawn look healthy.
  • It makes the grass hardier when exposed to cold temperatures.
  • Iron is toxic to weeds and moss and can kill them. It turns them black and makes them easier to remove. 

However, applying too much iron on your lawn can cause burning if it is applied when the lawn is wet or the temperature is above 80 degrees. 

Furthermore, adding excess iron to the lawn will prevent the grass from growing properly and heavy usage may cause further damage to your lawn. 

Excessive application of iron may damage, stain or kill your garden plants. Make sure that you adhere to the proper guidelines supplied on the package when using these products.

If you are not sure about the guidelines, we recommend that you stick to one pound of iron per 100m2 of grass. To achieve remarkable results, water the iron after application.

Iron Deficiency in Lawn: Causes and Diagnosis

Iron deficiency in lawns could be a serious issue. In this case, it is important to get the ideal iron supplement for your grass. 

Before you do this, make proper findings to know if iron deficiency is the problem of your lawn.

While many well-manicured lawns won’t have issues with iron deficiencies, altering the iron level of your grass may cause problems too.

You need to send soil samples off for testing to determine if iron deficiency is the problem of your lawn. Meanwhile, ensure that your lawn does not develop symptoms of other problems.

To further detect iron deficiency on your lawn, you will observe that new grass blades turn pale yellow instead of the rich green color that you are expecting. 

Here are some reasons for this:

  • This deficiency can happen when a new lawn struggles to become properly established.  This is caused by the pH levels in the soil that is not properly balanced. In addition, excess sand in the soil may also be a factor.
  • Excess rain and water can cause iron deficiencies. Nutrients can be washed away by water before the lawn can absorb them. If you didn’t notice changes after applying the iron solution, it could be a result of the weather.

When to Apply Iron to Your Lawn

It is advisable to apply iron to your lawn when the weather is ideal. 

Iron could burn your grass if the weather is too hot and it can wash away if there is excessive rainfall. Furthermore, a balanced level of ground moisture is required to enable the lawn to absorb iron.

As a result of this, many gardening experts recommend that you apply iron during the winter months when there is a better moisture level.

The application should also happen when there isn’t excess sunlight.  The mode of application depends on your area because some other areas may have drier and warmer winters than others.

How Often Can You Apply Iron to Your Lawn?

Many homeowners are not sure of when to apply iron to their lawn. Some experts suggest that you can treat your lawn with liquid iron every 4-6 weeks. 

Here are other factors to consider:

  • When applying irons for lawns, your grass should not be too dry or wet.
  • The rate at which you can apply iron on your lawn depends on the levels of iron in the soil and its pH.
  • It is best to apply iron on domestic lawns once in each season. This is equivalent to applying it four times a year. You can apply iron up to ten times each year if the lawn is particularly deficient.
  • This supplement shouldn’t be used as a standalone fertilizer. It is best to combine it with a regular fertilizer as a supportive treatment.

Types of Iron Fertilizer

There are several types of iron fertilizer for lawns. It is advisable to know the difference between them before you start applying on the lawn. This will help you know what supplement is best for your lawn. Here are some of them:


This type of iron fertilizer does not work in alkaline lawns because of its ineffectiveness in pH below 6.5.

Chelated Iron

This iron fertilizer for lawns is a compound that protects your lawn against oxidation and rain. 

In addition, it helps to stabilize ions. Chelated iron contains different things including ammonia, amino acids or citrate, FE +3, and sodium.

Ferrous Sulphate

Ferrous Sulphate is a common and affordable iron fertilizer suitable for lawns with a pH lower than 7, or else, it won’t be that effective. It contains around twenty percent of iron.


Applying iron to your lawn will improve grass growth and boost its health and at the same, excessive application can also burn the grass. 

The best way to the right application on the lawn is to follow the step-by-step guidelines laid down by the manufacturer.

Frequently Asked Questions

Does Iron Make Your Grass Greener?

Yes, iron on your lawn can make your grass greener. For instance, applying two pounds of chelated iron per acre will make it look greener.

What Happens if You Put Too Much Ironite on Your lawn?

Ironite contains urea nitrogen which dissolves quickly when wet. It has a high possibility of burning your grass if you apply too much of it.