Too much iron in lawn will cause your healthy and green lawn to suffer severe chemical burns. Iron is an essential micronutrient that grass and plants need to grow healthily.

Too Much Iron In Lawn

Many times inexperienced lawn owners end up adding iron excessively to the soil. Find out how to reverse iron toxicity using advice from seasoned professionals. 

What Are Signs of Too Much Iron in Lawn

💥 Quick Answer

Sign of too much iron in lawn are uneven lawn appearance, and the grass would look burnt by some patches. In addition, the acidity of the soil would be disturbed, and the iron would be straining the surface of the lawn. 

– Uneven Lawn Appearance 

Even slightly raised amounts of iron can be unhealthy when combined with unwanted conditions in the lawn. Temperatures above 95 degrees and below 55 degrees Fahrenheit, when combined with raised iron levels in the soil, will cause severe chemical burns to the grass leaves.

When applying iron to the soil, the grass must be neither too dry nor too wet. This also compounds the burning potential of iron. If you have planted the wrong grass type for the region where you live, then this grass will also be at a higher risk of toxicity from iron. 

Too much iron within your lawn soil occurs from the overuse of liquid iron supplements or iron fertilizers. Without proper soil testing or reading the manufacturer’s guidelines, there is a high chance you will end up adding too much iron to the soil and it will result in your lawn to look very uneven.

– Grass Appears Burnt 

When too much iron is added to the soil, it is taken in by the grass in large quantities. Within grass, it first increases the amount of chlorophyll in the soil and then burns the leaf blades. You will see the grass turn darker first and then burnt out.

The grass will become darker green at first and then fade to brown and even black, or even purplish for three to four days. Afterward, the grass turns yellow or light brown and assumes a crispy texture, and it will basically appear burnt.

Causes of Too Much Iron In Lawn

Unless there has been a particularly large spillover, your lawn will luckily not be affected in its entirety. These damaged areas appear in random patches on your lawn, having burnt grass where iron concentration has been applied particularly high in that particular part.

Note that iron is often used to eliminate moss from the lawn ecosystem, and people are mistaken for thinking that adding more iron will help kill moss faster, where it reality it will burn the grass instead. Mostly iron sulfate is the form used to add iron to your soil.

– The Soil PH Is Disturbed

A big symptom of iron excess is the dropping of the soil pH below normal levels. You need to be alarmed if the pH drops below 5.5, and this mostly happens when people apply liquid iron without diluting or following the instruction manual’s guidelines, and the soil will be weaker in its pH value. 

It is easy to figure out how acidic your soil has become and if the iron has damaged it. You can use the strips that measure pH are easily available everywhere and will give you a pretty accurate idea of where your soil’s pH lies. 

– Surfaces Stains

When too much iron is added to the soil, this can spread over to other parts of the lawn and stain them. Chelated iron begins to affect hard surfaces such as your patio, the driveway, and even the fence posts, it would even discolor and stain your grass, this is a feature as well. Don’t worry; any good-quality cleaning product easily removes most iron stains.

However, take this as a sign that your grass is in trouble and that you must act fast. Quite a lot of fertilizers contain iron as part of their ingredient list. In addition, you might have added too much iron if you were to use such a fertilizer simultaneously with iron sulfate, and is concentrated in this content. 

Note that the only reason your lawn might suffer from iron toxicity is because of over-application or accidental spillover as you were applying it.

Iron is a micronutrient that is needed only in minute quantities and boosts the color vibrancy of your lawn. However, just a little more iron than usual, and you end up producing unwanted toxicity.


How To Solve Too Much Iron in Lawn?

To solve too much iron in lawn, you first have to carry out lawn testing, water your lawn very well, apply some lime solution. In addition, you can treat it using bicarbonate, or zinc. Lastly, be careful with your next application of iron.

– Carry Out Lawn Testing Beforehand

Of course, by the look of your lawn being uneven or even dispatched and faded in colors, so you have caught all the symptoms of having excess iron in your soil.

However, for better assurance, you still need to confirm your diagnosis by performing a chemical soil test. One easy method is to buy inexpensive pH testing kits from the market and use them to check out the pH of your soil.

You must take some soil from the middle of your lawn and pour it in fresh water. Using distilled water will ensure that you get the most unadulterated results.

A probe-based pH meter will cost slightly more than pH strips but is way more accurate. It yields the best results when used to test slightly damp soil. Note that you will know you have an iron problem when the pH comes out to be less than 5.5, because it lowers the pH balance and makes it acidic.

Solve Too Much Iron in Lawn

– Water Your Lawn Thoroughly

Watering is the first thing you must do to lower the impact of having too much iron within your lawn and to adjust the balance of the minerals that the soil is carrying. Iron is more harmful to the grassroots when it is allowed to stay in the soil undisturbed for prolonged periods.

Instead, you must definitely flush it out of the soil. Use a large volume of water to flush the lawn at least two times. This will help reduce iron levels and make them somewhat tolerable for plant life, and your soil would recover as the iron drains out by being diluted with irrigation. 

– Apply Lime To The Soil

Adding iron to the soil decreases its pH levels; you need to take action when these levels fall below 5.5. What better way to do this than adding time-tested and trusted lime? Lime will add other much-needed nutrients like magnesium and calcium to the soil, in addition, it will adjust the right acidity level to your lawn. 

Dolomite lawn is the form in which lime is mostly added to the soil. Which means whether you go for powdered form or pellets depends on your personal preference.

It is safe to determine beforehand how much lime you will need. You can calculate this by measuring how much the pH needs to be lowered and the total area that needs to be covered, and this will solve the issue.

Instead of hand application, you better use a rotary or drop spreader as well. You can easily divide your lawn first in horizontal straight lines in which you walk, holding the spreader evenly. Then divide the lawn into vertical lines and walk the same as before.

Note that this method ensures that each part of the lawn gets evenly covered, and no part is missed. Sprinkle very little water over the entire lawn so that lime can get absorbed into the soil.

– Treat With Bicarbonate

Lime is not immediately available at home and might take some time to obtain. To take immediate action right after an accidental spillover, you can take help from bicarbonate instead, which is an organic matter as well, which means it isn’t a harsh chemical.

Bicarbonate works by binding to iron and decreasing it from hurting grass. Bicarbonate is not the healthiest substance to add to the salt because it directly impacts the soil’s pH levels, and it does it perfectly well.

You should do your research and calculate how much bicarbonate to add to the exposed patch of your lawn, especially the very damaged parts. Simply, you must mix the required quantities of bicarbonate in water and pour it only on the lawn parts where the spillover had occurred. 

– Apply Zinc 

Adding lime to the soil is the most important part of solving this problem, but it’s best to supplement it using zinc. Zinc decreases the concentration of iron toxicity in the soil pretty effectively. Note that it also helps adjust the disturbed pH levels of the soil better.

Commercial soil amendments that add zinc will make your life so much better, because zinc is a common micronutrient often deficient in most soils and often added artificially. Each product comes with proper instructions given at the back of the package. You need to give these instructions a careful read and follow them till the end.

In addition, only use the normal quantities of zinc recommended by the manufacturer just because you are treating an iron overdose. Zinc will stop the grass roots from absorbing iron and getting hurt. 

Another micronutrient that prevents iron from entering the roots is molybdenum. It is also much needed by the grass for its growth, but only in a small amount. Nonetheless, you can obtain soil amendments containing molybdenum and add them to the soil as per the lawn’s requirements. 

– Be Careful With the Next Iron Application

One of the best solutions to adding too much iron is to be extra careful in the future, because now that your soil has revoered, it still has gone through a shock, so the next time if you aren’t careful and you add too much of it again, the soil will be very much weaker. 

Add iron supplements to a lawn with this deficiency approximately four times a year, and always buy these supplements from a reputable manufacturer and follow their instructions. Directly applied liquid iron hurts grass; water it immediately to keep it safe.

Signs of Too Much Iron in Lawn

No lawn needs more than five times per year, and more than ten times per year is simply a recipe for disaster. However, to stay on the safest side, take help from an iron fertilizer once per season, which makes it twice yearly. 

In addition, other than watering the lawn immediately afterward, you may even mix it with a non-iron regular fertilizer to make it safer. Trust this process as it enables your lawn and grass to tolerate iron much better. 


Here is a brief recap of the essential steps you can take when there is too much iron in the soil.

  • An iron spillover in the soil will disturb its pH and produce chemical burns to the grass.
  • As soon as you spill iron anywhere, water that part using as much clean water as possible.
  • Lime is the most effective antidote to iron and decreases its quantity in the soil, but be careful of the quantity.
  • You can also take help from zinc and molybdenum as supplementary measures along with lime.

The next time an unfortunate iron spillover occurs on your lawn, keep your wits ready. Think back on all the tips in this article and use them to carry out as much damage control as possible. 

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