Chelated Liquid Iron for Lawns | How and When to Apply It

Among the garden center shelves filled with a plethora of soil amendments and fertilizers, there sits one that sounds familiar. But, you’ve never considered it, not knowing what it is or how it works. This is often the case with chelated iron. 

The allure of a healthy lawn is the lush, vibrant sea of green that increases the beauty and use of our outdoor spaces. Maintaining it includes things like deep watering, mowing, and fertilizing with the focus being primarily on the grass itself. But, what about the soil? That all-important substrate, providing a fertile home for turf grasses to grow in. The soil hidden beneath should include all the elements needed for them to thrive. 

If vital elements are lacking in your soil, then chelated liquid iron for lawns is invaluable. Lawns can only make chlorophyll (which makes it green) with proper access to iron. Without it, your sod will turn a faded yellowish color. A condition called chlorosis. Simply spraying on iron may be a quick fix but it won’t last long. Here, we’ll discuss ways to improve the iron content in your lawn’s substrate for long-term vibrancy.   

Why Add Liquid Iron to Lawns 

If that yellowish haze is spreading across your lawn, a good soil test will determine how much iron is naturally present. It may turn out that there’s plenty of iron in the soil but the pH level is too high. This blocks your lawn’s ability to absorb that iron, as well as water and other nutrients. Lowering the pH will improve iron uptake. 

If tests show an iron deficiency, this may be due to soil nutrients leaching out over time. This is particularly common in areas with heavy rainfall, resulting in a substrate not fertile enough to support healthy growth. Replacing it with the right product will not only improve the health of your lawn and soil but will also lead to an increased vibrancy in turf color without all the excessive growth that often follows high doses of nitrogen. 

What Does ‘Chelated’ Iron Mean? 

Iron in its pure form isn’t of much benefit to plants because it naturally rusts when exposed to water and oxygen. In small qualities, this wouldn’t harm your lawn. But if rust content is allowed to build up over time, it may lead to iron toxicity in the soil. Iron in ‘chelated’ form is far more beneficial as it is processed using the addition of non-metallic ions that create a protective barrier between the iron in your soil and oxygen. This prevents it from rusting in the soil. 

The chelating process also keeps iron from separating and leaching out, allowing it to remain where it is most accessible to the roots of your lawn. When choosing which brand of chelated iron to use, you’ll see listings like Fe-DTPA, Fe-EDDHA, Fe-EDTA, Fe-EDDHMA, and Fe-HEDTA, all of which are common formulas in some of the best types of liquid iron for lawns.

Is Chelated Iron a Fertilizer? 

Chelated iron is a specially formulated fertilizer that allows for optimum nutrition absorption. Referred to as ‘sequestered iron’ in the horticulture world, it’s become one of the most sought-after tonics for treating chlorosis in lawns. Effectively combating this yellowing phenomenon often needs just one application. 

So, what’s the difference between the various types mentioned above? The effectiveness of each type will greatly depend on your soil’s pH level. 

EDTA > effective in pH up to to 6.0

HEDTA > effective in pH up to 6.0 plus broadleaf herbicide

DTPA > effective in pH up to 7.0

EDDHA/EDDHMA > effective in pH up to 9.0 

How Does a Chelated Iron Supplement Work? 

When pure or untreated iron supplements are added to soil, they will eventually start to coagulate into a solid. Making any nutrients they may have once offered your lawn completely inaccessible. The process of ‘chelating’ iron is intended to prevent this from happening. While maintaining the consistent level of accessible iron your lawn needs for chlorophyll development. Which allows it to turn sunlight into food.

It’s important to test the pH of your soil so you’ll know which would be the best liquid iron for your lawn, out of all the different types. Otherwise, you run the risk of an iron toxicity situation.  

Types of Chelated Iron for Lawns

Chelated iron products work quickest in liquid form. As a result, you’ll see a greener lawn above ground because of happier roots underground. Chelated liquid iron can be purchased as a concentrate, at a slightly higher price point, or in a cheaper granule or powder form. Both of which are water-soluble. Another benefit to chelation is that it makes iron dissolvable in water, making it much easier to apply. Un-chelated iron won’t break down to a liquid form.

Just keep in mind that liquid iron doesn’t get absorbed through foliage, only the roots. But water does, so it’s nice to give your lawn a good watering while improving the soil. In a moment, I’ll be sharing my picks for the top three most effective liquid iron options for lawns. But, this does come in spike and pellet form as well, for a more slow-release effect. 

Liquid Concentrate 

Diluted liquid concentrates immediately nourish roots through quick absorption. You may see the reversal of those pale yellow patches within days. Some are even formulated to safely combine with fertilizers, insecticides, and fungicides. (Of course, research is important, to make sure your choice is compatible.) 

Liquids tend to remain in the soil longer for extended root access. And are easily applied using a watering can for smaller areas or as a drenching spray using a hose attachment. Because of the labor-intensive process of making a chelated iron liquid concentrate, different options can be a bit higher on price. But, the quick results are often worth it. 

Granules or Pellets 

As with other fertilizers, there’s a benefit to slow-release forms of chelated iron too. Working the recommended amount into the soil of lawns can offer them a consistent stream of iron. This is a really time-saving method as it only needs to be applied once and then nutrients are released with every watering.

If you apply them before the rainy season, your effort would be minimized even further. Dry forms are also easier and less messy to store during the off-season as well as having a longer shelf life. The great thing about these is that they’re also water-soluble for when your lawn needs that quick fix. 

Spikes 

Iron spikes are another great slow-release option. While they’re typically not water-soluble, they are larger and can therefore offer your lawn ( as well as trees and shrubs) sufficient nutrients with fewer spikes applied. Making them a time-saving and cost-effective choice. And again, if you get them in before a good rain, you don’t even have to water them in. 

These can be purchased containing iron alone or supplemented with other trace minerals like manganese, magnesium, and potassium. Photosynthesis will be steadily restored, resulting in your yellowing lawn greening up in no time. Especially when you choose one appropriate for the pH level of your soil. 

When to Apply Liquid Iron to Lawns 

Optimum results, on most lawn varieties, are achieved when iron is applied under the right conditions. Outdoor temperatures should be between 15° and 21°C (60°-70°F), making spring the perfect season to start applying liquid iron to your lawn. If the previous autumn left you with an iron-deficient, yellowing lawn, spring applications will also allow you to watch everything in your garden green up at once!

Avoid use on frigid winter days or in the extreme summer heat.  This will affect how chelated iron fertilizers work and inhibit their success. Iron that settles on grass blades on really hot days can cause burn damage. If your landscaper or gardening specialist has recommended that you use it at lower concentrations, over time, then at specific intervals between spring and early autumn is best. Especially when your lawn has been mowed and watered first. 

How Often to Apply Liquid Iron on Grass 

The results of a good soil test will not only measure your soil’s iron content but can also guide you as to the quantity to be applied and how often. Of course, you’ll always want to follow label instructions to avoid overdosing. Typically, 30 days in between each application is recommended. But, here are some solid rules-of-thumb to follow:

• If your lawn is more green than yellow, 3-4 applications per growing season should be sufficient.
• If it’s more yellow than green, either a higher dose per application or higher number of applications may be required to achieve a uniform greening effect. 

How to Apply Liquid Chelated Iron 

Next, I’ll be sharing my top three picks for the best performing chelated iron products out of the many that I’ve tested. Some come in a concentrated form that needs to be diluted with water. While others come pre-mixed and ready to go. Both can be evenly applied across your lawn, as you walk back and forth, using your hose and a quart-sized sprayer attachment. You will want to wear protective clothing though, as liquid iron can cause skin irritation. 

Concentrates will typically advise mixing anywhere from ½ teaspoon to 2-3 ounces with a significant amount of water prior to use It would seem that the smaller the amount to be diluted, the longer the jug will last. Making it seem more economical. Yet, some that required diluting higher amounts actually performed better. Focusing on value-for-money is going to be your best bet. 

How Long Does Chelated Iron Take to Work 

The length of time between applying chelated iron to your lawn and seeing results will depend on two factors. The severity of your soil’s iron deficiency and, most importantly, its pH. This is why it’s important to test your soil first. Choosing the right liquid iron product that works with your soil’s present pH level is critical to how quickly it works or if it works at all. 

Once that’s determined, the right product should result in a greener and more lush lawn in about 2-4 weeks. This is due to the time it takes for the chelated iron to react to the soil’s pH and make the iron available for root absorption. Then, of course, your lawn needs to process and benefit from it. In my experience, it’s well worth the wait for a healthier lawn and more fertile soil. 

Will Too Much Iron Hurt Your Lawn?

Just as with any other soil amendments or lawn fertilizers, they only work the way we want them to when applied at the proper dosage and proper time. Many products claim, in big letters, that they don’t harm lawns. But, the tiny print will disclose that this claim only applies when the product is used as instructed on the label. Common sense, right?

You should also be aware that while your lawn may stay nice and green for a time, after overdosing with iron, underneath the roots are burning away and dying. In my experience, you can’t go wrong following the product instructions.  

Can Iron Burn Grass?

Yes, chelated iron can absolutely burn grass under certain conditions. Outside of overdosing, other factors like temperature, moisture and unnecessary nutrient additives may contribute as well.  

• How liquid iron works changes based on temperature. Applying it when outside temps are too hot or too cold may result in burned grass.
• Applying liquid iron to dry lawns can cause the roots to absorb too much at one time, resulting in burning. Watering just before or just after will ensure that the iron is being absorbed in an effective manner. 
• Nutrient additives, like boron, that your soil already has may also result in root and grass burn. 

Does Liquid Iron Lower Soil pH?

If soil testing reveals your soil to have a high pH, lowering it is your only option for a healthier lawn. High pH levels block the absorption of iron or any other nutrients. If you need to lower your soil’s pH, there are several ways you can do this. Liquid iron alone can’t.

Choosing an option that has built-in, pH lowering additives already in it, like iron sulfate, aluminum sulfate, or sulfur, can be a really cost-effective option. You’d be achieving two goals for the price of one. There are also different options that work with varying levels of pH, up to 9.0. 

3 Chelated Iron Formulas Reviewed 

Product testing and review research is labor-intensive, so I’ve done some experimentation of my own to share with you. Including feedback from across the lawn care world. For your convenience, here are my picks for the top 3 best liquid iron options. 

1. LawnStar Chelated Liquid Iron for Lawns 

We’ll start with an option from LawnStar that gains its iron content from ferrous sulfate. This means that it will help lower pH while allowing your lawn unrestricted access to the iron. The results I saw were balanced nitrogen levels and increased chlorophyll production for vibrant, lush turf with a stronger root system and environmental stress tolerance. 

Versatile enough to also be used on ornamentals, trees, and vegetables, this is one of the few products that chelates iron by way of sodium glucoheptonate instead of EDTA making it people and pet-friendly. 

This option provides stability in alkaline soils up to 9.5. But, you’ll still want to test your soil’s pH first to see if this is appropriate. Make sure to don protective clothing before applying and put tarps over any stone pathways nearby because this tends to stain. Click here for Lawnstar Chelated Liquid Iron for Lawns.

How To Use: Mix the concentrate with water, following the supplied guideline rates on the label and apply evenly using a hose attachment. 

Customer Reviews: Customers who tried this for the first time we’re really impressed with how fast they saw greener, more lush results. In 5 days vs the stated 2-4 weeks. And being EDTA-Free means its people and pet friendly. 4.5 out of 5 stars and my choice for BEST BUY.

Pros      

• EDTA Free – People and Pet Friendly
• First results seen in just a few days

Cons

• May stain hard surfaces and skin
• May be at a slightly higher price point 

2. Southern Ag Chelated Liquid Iron 

In the early morning, I tested this option on my back lawn which has an approximate expanse of 8000 sq. feet. With a dilution rate of 1 tablespoon per gallon of water, the 4 liter (1 gallon) jug was enough to cover the whole area. Research revealed that applying this in the heat of mid-day may cause blade scorching; cooler temps promote faster absorption.

This EDDHA formulation with 5% iron is combined with sulfur to lower pH. Yet, remains stable in pH up to 9.0. And like the LawnStar option, can also be used in other areas of your garden that may be iron deficient. Check out Southern Ag Chelated Liquid Iron here.

After using this as a soil drench, the yellowing patches in my lawn began to green up within a week. With a full greening happening in two. But, just like the first option, I had to cover any hard surfaces prior to the application due to the risk of severe staining. 

How To Use: Mix at a ratio of 1 tbsp per 4 liters (1 gallon) of water. Then, apply as a drenching spray in the early morning when temps are cooler.  

Customer Reviews: Lawn care enthusiasts are raving about how vividly green their lawns get. And were very surprised to see that it also eliminated most of their weeds. 4 out of 5 stars.

Pros      

• Remains stable in pH up to 9.0
• 5% iron plus sulfur

Cons

• Can heavily stain hard surfaces and skin 
• Non-compatible with other fertilizers 

3. Simple Lawn Solutions Micronutrient Booster Liquid Turf Spray 

My final pick has iron, nitrogen, and micronutrients, all in one ready-to-use jug with a built-in hose attachment. I enjoyed using this one for its ease of use, allowing me to fertilize my lawn while also revitalizing those areas of lawn chlorosis with added iron. I tested all of these on Bermuda grass but they’re safe to use on every grass type, from centipede to zoysia. 

After a week or so, I noticed that the size of the new grass blades was longer and thicker than those grown in areas where I tested the others. This was evidently due to all the nitrogen present in this mix. Iron alone is a good way to green your lawn up without a lot of vigorous growth.

I could see where this Simple Lawn Solutions would work very well if your lawn is not only yellowing but thinning too. The only downside is that it doesn’t have the ability to manage soil pH. See prices for Simple Lawn Solutions Micronutrient Booster Liquid here.

How To Use: Simple Lawn Solution products can be attached directly to your hose to spray onto your lawn without mixing the product manually. 

Customer Reviews: Gardeners who are new to lawn care are very pleased that they can improve their soil and green up their grass all with one product. And they can’t say enough about the quality customer service support. 4.2 out of 5 stars.

Pros      

• Supplemented with Nitrogen, Zinc and Manganese
• Fertilizes and enriches soil 

Cons

• Does not balance soil pH 

Liquid Iron for lawns FAQ’s