Ironite vs. Milorganite: Which Organic Grass Fertilizer Is Better? (Explained)

milorganite vs Ironite

Ironite and Milorganite are two organic fertilizers made from different byproducts. Ironite is a mineral-based fertilizer widely used to supplement iron when your lawn soil tests indicate plant iron deficiencies or as soon as you see pale yellow color instead of a dark deep green color, while Milorganite is an organic slow-releasing nitrogen fertilizer made from the processed sludge of wastewater treatment plants.

If you’re looking for a more natural alternative to chemical fertilizers, then considering buying Ironite or Milorganite is your best bet.

However, organic lawn fertilizer is not just about wanting an easy-to-use product that doesn’t require any additional work on your part. 

There is more to your lawn benefits when you choose to use one of these organic lawn fertilizers. So, which one is better when you compare Milorganite vs. Ironite organic lawn fertilizer? 

Ironite is better than Milorganite. Ironite lawn organic fertilizer helps achieve a lush and dark green lawn with slow growth. Ironite lawn fertilizer requires less water, it can work on all types of soils and the grass is not burnt. 

On the other hand, Milorganite is not far behind either. Milorganite is better when you need to provide a quick boost to the micronutrients of the soil plus the soil is not burnt. To know more, read on. 

1. What is Ironite and Milorganite.

To understand the benefits, nutrition compound makeup and main differences between Ironite lawn fertilizer and Milorganite, we need to break down each of these organic lawn fertilizer.

Ironite Organic Lawn Fertilizer Review.

Ironite is a type of fertilizer that contains a high percentage of Iron and aids in keeping your plant green by helping in the photosynthesis process. 

It achieves by the production of enzymes that work in synthesizing the proteins for the production of enzymes that help in the synthesis of proteins for the production of chlorophyll. 

This type of Ironite in discussion is organic as it is obtained from organic sources. This is great as the plant absorbs the iron quickly although it is released over a long period. 

A less known fact is that Ironite is an incomplete fertilizer. Alternatively, Ironite can be a lawn supplement that can be applied to your lawn together with the fertilizer, in this case leading to Ironite organic lawn fertilizer. 

The formula of ironite is 1-0-1 which implies that potassium and nitrogen are in a lower concentration. Your grass is made to grow green fast due to the high concentration of water-soluble iron in the ironite. 

Best Time to use Ironite

An addition of Ironite can be made to the application of your regular fertilizer or if need be. It is recommended that Ironite must be used four times a year, while combined with your regular feeding schedule and make sure it must not be applied more than 10 times per annum. 

Why Use Ironite for Lawns Instead of Regular Fertilizer?

The question that obviously must be on your mind is why we are choosing Ironite over the regular N-P-K fertilizers. 

The reason is Ironite works best in greening your lawn than how traditional fertilizers would do it. Ironite deals with the root cause of the pale color. 

A test must first be conducted to see if the pale yellow grass color is being caused by the deficiency in iron. 

The difference is based much on the rate of growth. A lot of nitrogen is added to your soil which leads to the fast growth of the grass which means frequent mowing of the grass while Ironite also encourages green lawns but that grows slowly which means less mowing of the grass. 

Milorganite Lawn Fertilizer Review.

Milorganite is a type of lawn fertilizer that is organic, which implies that it is manufactured from microbes that are recycled naturally. 

It comprises nitrogen which encourages growth, iron which helps in keeping your lawn greener, and potassium which provides strength, plus other numerous micronutrients which work in making sure the lawn is healthy. 

The nutrients profiles of lawn fertilizers are expressed as numbers concerning their NPK, that is Nitrogen, Phosphorus, and potassium. 

The formula of this fertilizer is 6-0-4 which means there is at least 6 percent of nitrogen, potassium in 4 percent, and phosphorus which is less than 1 percent of phosphorus. In addition to these mentioned nutrients, it has iron which is 4 in percentage. 

Is Milorganite Safe?

The debate over the safety of Milorganite, a fertilizer made from wastewater sludge, has been going on for years. And, if you are wondering whether Milorganite is safe, you are not alone.

Milorganite is safe to use in your yard. Whether you have pets or small kids at home, Milorganite lawn fertilizer is not harmful as it has been tested and approved to be safe to use as a byproduct from treated wastewater. 

While the term wastewater materials may raise some health concerns for its potential users, Milorganite organic lawn fertilizer is safe to use. 

If you’re still concerned about Milorganite safety, there are other safer, natural organic fertilizers for lawn, you may want to consider as an alternative. Compost or manure are one of many best Milorganite alternatives and here’s why: 

Milorganite has high salt content and ammonium sulfate which can be harmful to your plants when applied excessively. The salt levels in the soil will increase and could burn plant roots if they are not watered properly. 

Ammonium sulfate can also cause damage to trees, shrubs, flowers and vegetables over time because it kills beneficial bacteria on the leaves of plants. For these reasons alone people often choose other types of fertilizers over Milorganite when gardening their lawns

When to Use Milorganite

The best time to use Milorganite is spring time. Milorganite works well with your lawn when you first see signs of warmer weather and greening lawn sprout shoots coming up. In general, Milorganite fertilizers are best applied in the spring as soon as your grass starts to grow and when daytime temperatures consistently reach 60 degrees Fahrenheit or higher. It will be easier for you to take care of those pesky weeds that sprout up during fall, too!

Milorganite can be used 4 times a year. It is recommended that it has to be used when the grass has gotten green and has an active growth and when the temperatures have surpassed 6 degrees Fahrenheit. You can apply for the last time during the Thanksgiving period which helps to keep your lawn healthy during the winter period when it is dormant. 

In terms of warm-season grasses, it is recommended that you apply them four times a year, and this process can be started in late spring. 

2. Benefits of Ironite vs. benefits of Milorganite

For many homeowners who are looking to make their lawns beautiful again. The harsh winters can be difficult to maintain that healthy green color in your lawn and garden. 

So If you’re looking for the best lawn fertilizer to add nutrients back into your soil, then Ironite and Milorganite are perfect for you. These two organic lawn fertilizers have all of the minerals and nutrients needed to help get things growing again this summer!  

But if you’re not sure which one is right for your needs, Ironite and Milorganite offer some great benefits. 

Benefits of Using Ironite for Lawns

Ironite is a popular fertilizer that many people use in their gardens. It has been around for years and continues to be popular due to its benefits like being organic, non-burning, and being easy on plants. In contrast, Milorganite is not as well known but offers some great benefits too! For example, it is also organic and can help reduce the compaction of soil.

Ironite for lawns is a type of fertilizer that does not demand much water. Less water is needed by plants treated with Ironite. This helps you in cutting costs when it comes to water bills. 

  • It can be used on all types of soils. 
  • It can also be used on other plants. Ironite can not only work on grasses but other plants like trees or shrubs. 
  • The grass is not burnt by this fertilizer which is a highly recommended trait. 
  • Another benefit of Ironite is that your grass will be made greener but the growth will be maintained at a slow speed. 
  • Ironite has a faster work rate. The appearance and feel of your lawn are improved by its synthetic formula in just several weeks, and this does not require much water. 

Benefits of using Milorganite for lawns

Milorganite has a formula that releases at a slow rate and your lawn is kept healthy for a long time and the micronutrients go into the ground at a faster pace after being applied. It remains in the soil for as long as 10 weeks providing nitrogen and iron when needed by your plants. 

Soil is not burnt by Milorganite since it has a low salt content which is unlike the case with synthetic fertilizers if they are applied in excess quantity or high heat. Concrete also won’t be stained if there is contact. 

3. Drawbacks to Ironite and drawbacks to Milorganite

There are drawbacks to using Milorganite or Ironite organic lawn fertilizer. Although it is considered to be a safer, biodegradable alternative to chemicals in synthetic lawn fertilizers, Milorganite and Ironite organic lawn fertilizer are produced with the sludge waste from municipal sewage treatment plants.

The material used to make these products may look inferior as it is initially supposed to go for dumping. Instead, it is processed and made ideal for organic lawn fertilizing.

There’s no shortage of recommendations or benefits of using Ironite and Milorganite long term. Comparisons between Ironite and Milorganite fertilizer have been made by experts and Lawn Care Services companies across the country.

So, if you are considering introducing Ironite or Milorganite organic lawn fertilizer to your backyard care, It’s important to know which one you should use to fertilize your lawn organically for a healthier, better-looking lush yard!  

A number of factors go into this decision including cost, environmental impact, and effectiveness. The difference in price can be significant if you go with what is more expensive and not necessary as effective- so it pays off to do some research before making a purchase!

For example, the cost per pound for Ironite is $0.91 but that same amount of Milorganite only costs $0.32- while both have similar organic ingredients, one is definitely cheaper than the other! Other benefits include:

Ironite releases nitrogen  for 6-8 weeks Milorganite releases nitrogen for 3 months

Ironite doesn’t burn the lawn Milorganite can cause some scorching/burning (especially if doing a large area)

When you weigh these factors, it is clear that Ironite will be more effective than Milorganite in most cases and therefore a better choice!

Drawbacks of Using Ironite for Lawns

Ironite stains concrete: if there is contact between the Ironite and concrete, the concrete can be permanently stained including the walkways. 

It is not the right choice for people who would prefer to stay organic. 

Lawns are at high risk of being damaged and getting a grayish tone since it is easy to go overboard. 

Although this fertilizer is deemed to be safe in terms of home use, it has been labeled as one of the sources of metal leakage, more especially lead and arsenic. 

Drawbacks of using Milorganite for Lawns

Milorganite does not provide a quick boost when it comes to growth and color like the way synthetic fertilizers or nutrient supplements would do it. Milorganite won’t be effective if you wish to have your lawn looking dark green and healthy as soon as possible. 

4. Which organic fertilizer is better, Ironite or Milorganite, and why.

It’s fair to say that Milorganite and Ironite are complete opposites. One is a slow-release fertilizer, the other quick. It may be hard for some people to decide which could serve them better depending on their needs.

One minute you’re using one product as organic lawn fertilizer high in iron; then before long, it seems like you need an iron supplement because your lawn has grown so quickly with this second product!

In general, Ironite organic lawn fertilizer is better than Milorganite. The main difference between Ironite Vs. Milorganite is how they work. Milorganite is a high-iron organic lawn fertilizer that slowly releases nutrients to keep your yard healthy. Ironite, on the other hand, provides fast-releasing quality in order to make sure you have excellent green grass faster than ever before by providing all of the necessary minerals needed for lush and vibrant plants.

Reaching this far, you must have an idea on which one is better, but here are few tips to help you make an informed decision and which one would be suitable for a particular situation. 

For A Greener Lawn

If you want your lawn to have that dark green and thick feel, use Ironite. Yes, Milorganite also has a high concentration of iron but it is slow in boosting the strength of your grass. 

For Improved Soil Quality

The first thing first is to take care of your soil if you want to have a great lawn and this can be achieved greatly by Milorganite because it has multiple micronutrients. Although Ironite might provide that fast boost in terms of nutrients to your plants, a complete fertilizer would be ideal for the soil to be healthy for some time. 

For a Shortage of Nutrients

The path that you choose is greatly affected by the type of nutrients that your lawn needs. Iron deficiency might be shown by lack of the green color and thickness in the blades. When you are in such a situation, Ironite is highly recommended which can be applied together with your normal fertilizer. 

If you have noticed that your lawn is patchy and growing slowly, it is recommended that you give your lawn Milorganite. Lawns need to be fed at the right time of the year if you wish for them to be healthy, hence the need for patience and complete fertilizer. 

5. Where can you buy either one of these fertilizers in your area 

These can be purchased online or from any of the agro dealer shops in your local area. 

Can I use Ironite and Milorganite together?

Ironite and Milorganite are both great products, but are they safe to use together? 
Ironite and Milorganite can be used together when there is no history of use in the past. However, if you have used any organic or synthetic fertilizers before, you should not combine Ironite and Milorganite together. In general, it is not recommended to use Ironite and Milorganite together.
Ironite is available as a granulated or liquid iron supplement that helps plants grow stronger and healthier than ever before. It’s perfect for fertilizing your lawn or garden to give it the boost of nutrients it needs to thrive in any climate.

On the other hand, Milorganite is an organic fertilizer made from processed sewage sludge that promotes healthy soil by providing all the necessary nutrients for plant growth. Together they can cause nutrient burn which leads to stunted growth and yellowing leaves on your plants. 

If you’re looking for a new way to fertilize your yard, consider adding Ironite to replace part of your yearly application of chemical fertilizer with something more eco–friendly. 

There’s nothing wrong with wanting to change from using Ironite to using Milorganite vice versa. But if you’re still using Milorganite as fertilizers, contacting your local authorities like the Milwaukee Metropolitan Sewerage District (MMSD) to find out how to switch to a fertilizer that will help your plants thrive without the possibility of causing nutrient burn is the best way to mitigate lawn damage.
Milorganite is an organic fertilizer made from processed sewage sludge that is safe to use all seasons.

Can you put too much Ironite on your lawn?

As a green-thumbed homeowner, you know it’s important to keep your grass alive and well. You might have seen the commercials for Ironite, which promises that its product is different from all of those other fertilizers out there because they are safe enough to use near children and pets! But, can you put too much Ironite on your lawn?

In general, you can not put too much Ironite lawn fertilizer on your lawn. Ironite is not a typical fertilizer that burns your grass when used excessively. However, if you use too much of it or apply it incorrectly to the soil, then this will result in a gray-like hue to the lawn due to too much iron supply in your lawn. Too much iron effects on your lawn can be difficult for some people’s eyesight.

If you want to get rid of these effects just wait; don’t add more Ironite until the color returns from the light green back into a lush deep green again!

How much Ironite fertilizer is too much?

To be clear, Ironite is not a typical burning type of fertilizer and if you use just the right amount of it, it will not burn your lawn. 

In general, a recommendation of about 1 pound per 1000 sq ft or 5 – 8 lbs per acre of Ironite in granular form is how much you need to make sure you are not applying too much Ironite fertilizer.

When should I add Ironite to my lawn?

Adding Ironite to your lawn yard helps change the pale yellow color of your grass to a more attractive deep green lush color. Sadly most homeowners have no idea when is the best time to apply Ironite to their lawn.

In general, you should apply Ironite to your lawn when your lawn soil indicates a shortage of iron. Testing your lawn soil for iron deficiency helps to inform when to apply Ironite. Soil testing and observations for yellowing of your lawn are the only indications that you need to add supplemental iron nutrients. As soon as you notice your lawn turning into a pale yellow color instead of the deep dark and lush green.

Before applying your Ironite to the lawn, you should make sure that there is no issue with water or nutrients. Typically the best practice when applying organic lawn fertilizer is to wait until after soil tests indicate an iron deficiency in the area where you want to plant it.

Can you apply Ironite and fertilizer at the same time?

There’s nothing wrong with wanting to make your lawn as beautiful and green as possible. And for most novice homeowners, it can lead to over-zealous practices that may jeopardize their lawn. However, more and more lawn enthusiasts often wonder if Ironite and fertilizer can be applied at the same time.

In general, Ironite and fertilizer can be applied at the same time. The use of granular fertilizer and Ironite will not affect or damage your lawn. Ironite supplements your lawn where plant Iron deficiencies are prevalent while Fertilizers promote lawn growth by realizing nitrogen and other plant nutrients your lawn needs to thrive.

“Ironite will not be activated until it is wet, so if you happen to spot the product on your lawn and fear that it may burn your lawn, do not worry. It won’t,” according to the company’s website.

When you choose to combine the application of fertilizer together with Ironite for a deep dark lush green lawn, keep a steady watering of your lawn to assist the applied Ironite work while it is actively releasing nutrients into your lawn as well.

If it’s yellowing out because of a lack of iron then there are two things that need to happen; firstly water more often so new roots can grow, secondly apply an iron-rich fertilizer such as Ironite (which also contains other nutrients). Apply before soil testing when indicated by deficiency.

What is a good source of iron for plants?

Plants that are short of iron, turn pale and yellow in color, indicating the deficiency of iron, a plant nutritional compound that helps lawns, shrubs, and trees turn into deep green and lush colors. But, to achieve the deep green and lush lawn, you need a good source of iron for plants.

In general, Ironite and Milorganite are the best sources of supplemental iron compounds for plants. Ironite, a plant iron deficiency supplement for lawns and backyard shrubs, and Milorganite, a sludge-based organic fertilizer for lawns, is high in iron for plants. 

For those who do not want chemicals on their lawn or backyard shrubs, Ironite and Milorganite are your best bet. Still, if these organic lawn fertilizers are not what you need to add iron to your lawn soil, there are other options such as composted manure or compost heap.

Milorganite contains several beneficial trace minerals such as zinc, copper, and boron which are also good sources of iron. With Milorganite you get the added benefits of a fertilizer blend like Potash Plus or Lawn Restore.

Milorganite also contains humic acid, lignin sulfonate, and fulvic acid – all great natural plant food ingredients that help restore the shortage of essential plant nutrients for your lawn.

Can I use Ironite in the summer?

There’s a good reason why using Ironite in the summer months – can be worrisome. And that’s because most homeowners do not want to apply organic lawn fertilizer today, only to find that when it gets hot outside, the organic fertilizer is burning the lawn instead of boosting its dark green color.

Generally, you should use Ironite all year round. Ironite can be used in the summer, or in the winter. The best time to use Ironite is in the spring when your lawn and backyard blossom is about to shoot sprouts.

For best results, always test your soil for iron deficiency before applying Ironite. And make sure to store your Ironite correctly when you bring it home from your local home and garden shop. You’ll want to keep it in a cool place, but also somewhere where there isn’t too much sunlight or heat coming from room air conditioners or nearby windows.

How to use Ironite fertilizer?

The first thing to do is to choose the form of Ironite to be used. When the soil has a high pH or is Sandy, liquid Ironite has to be used. This is done with the aim of blades absorbing Ironite more efficiently as roots find it difficult to absorb Ironite when in alkaline soil. Granular Ironite can be used on loamy or clay soil. 

Protective boots and gloves have to be worn. 1 ounce of spray has to be used per 100 square feet; the Ironite has to be swept off from the concrete surfaces and walkways. When the spraying has been done, there has to be a deep watering done and it must be allowed to take action.

People and pets must be kept away from the lawn for a couple of days since it can be fatal when ingested or after touching the skin. Improvements will be seen within a few days. 

How much Ironite to use on the Lawn?

Ironite is a fertilizer that is made up of iron sulfate and ammonium sulfate. Ironite contains the nutrients nitrogen, phosphorus, potassium, calcium, and magnesium.
It also has trace amounts of boron for plant growth. The amount to apply on your lawn will vary depending on how much you need to fertilize your lawn and what type of soil you have in your yard.

In general, apply 1 pound of Ironite per 1000 square feet. Typically, an ordinary Ironite is 4.5% iron by weight. This means that you need to apply about 1 pound of Ironite per 1000 square feet for 0.7 ounces of iron. Though it can be tempting to use more Ironite for better results, do not apply more than 2 pounds per 1000 square feet. Excessive use of Ironite can negatively impact the quality of your lawn.

It’s important to use the right amount because too little Ironite can result in yellow leaves or stunted plants while too much Ironite could kill grasses or other types of plants by burning them out with an excess of sulfur from the iron sulfate component. You should always read the package directions before applying any kind of fertilizer like Ironite so that you know the exact quantity you need to apply for a dark green lush lawn.

How much nitrogen is in Ironite Lawn Fertilizer?

Ironite Lawn Fertilizer is a nitrogen-rich fertilizer that provides your lawn with the nutrients it needs to be healthy and green. Ironite is extremely effective for people who want their lawn to look great without all of the hard work, but just how much nitrogen does Ironite provide? 

Ironite contains 1% Urea Nitrogen Compound. It is an excellent iron rich plant supplement with beneficial plant nutrients including organic lawn fertilizer that contains a low nitrogen concentration. With one percent urea, Ironite does not contain enough of this nutrient to make your lawn burn and it dissolves quickly into moist soil for easy application! 

For best results with your backyard, you should apply 0.1 pounds of nitrogen for every 1,000 square feet if you follow the instructions properly when applying Ironrite fertilizers as per the directions on its package or refer to the guidelines inside the package. 

Before purchase however, do a bit of research so that you know enough of how much product will be necessary based upon where in America’s heartland (in contrast with Alaska) – which has vastly different growing conditions than other parts of the country you reside.


Ironite is an excellent option for organic lawn care than Milorganite organic lawn fertilizer. However, Ironite organic lawn fertilizer may not be the best choice if you have heavy clay soil or you are growing veggies like zucchini for your preserves. 

Milorganite’s fertilizer contains more nitrogen and phosphorus, which are perfect for heavier soils. If your yard has light or sandy soil, go with Ironite because it will give your plants all they need without weighing them down. 

The team and I here @ Modest Home Digs publish exclusive weekly, well-researched guides to help our readership find out how we can help turn that tired-looking patch of dirt into an oasis of lush green Lawn and more! 

Eddie Mcfarren

Eddie Mcfarren is an avid Pet blogger who is passionate about pet welfare and everything to do with animals. His passion for writing does not intend to provide veterinary advice. However, when he writes about pets, he will go to great lengths to help users better understand their dogs. His pet dog Tess helps him in understanding a great deal of care and living with pets at home. On a serious note, the content on this blog is not a substitute for veterinary guidance. Only competently trained Vets can offer qualified advice about your pet's ailments. Therefore, make sure to seek advice from your local veterinarian officer near you!

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