Ironite Vs. Milorganite: Key Distinguishing Points & WARNING!

To have a healthy green lawn, it needs both water and sunshine. For various reasons, your lawn may not get them enough. It needs an extra boost to overcome that deficiency.

Both the Ironite fertilizer and Milorganite lead to a green lawn by giving the much-needed extra boost. And the green color also indicates a healthy lawn too. In this article, I will talk about them in-depth including key differences between Ironite vs. Milorganite.

Milorganite Vs. Ironite Comparison

ironite vs milorganite

Each of them is from a separate brand and each brand is prominent in lawn care products. The Pennington Seed Incorporated produces the Ironite lawn supplement and Milwaukee Metropolitan Sewage District produces Milorganite.

However, both of the products serve different purposes and work in a very different way. Whereas Milorganite is a lawn fertilizer, Ironite is not. It’s simply an additive to be applied in addition to fertilizer application.

Apart from that, here are some key differentiating points you might be interested to know:

  • Basic Comparison: Objectives & Ingredients

If you are interested in organic lawn fertilizer, you should be interested in Milorganite. It uses microbes and it’s the microbes that absorb nutrients from the wastewater.

With the slow-release method, Milorganite strengthens the root of your lawn grass over time. It takes a few weeks to see its magic. Since it is enriched with iron, it helps a lot to green up the grass leaves at a steady pace.

On the other hand, you apply Ironite only when the grass leaves turn yellow. As a great supplement enriched with iron, within days you will see a great result. The main purpose of applying it is to re-green your lawn grass.

  • The Ratio

Milorganite is a 5-2-0 fertilizer whereas the ratio for Ironite is 1-0-1. The first one has 4% iron whereas the latter has 4.5% iron with other micronutrients. For such a low number, many people don’t call it fertilizer. It’s basically an additive.

  • Time To Use

Now that you have a basic understanding of what they do, let’s see exactly when you should use them depending on your lawn condition.

If you notice your lawn is not green or starting to turn yellow, applying Ironite will be a much better option. Within weeks, you will get your result. Apart from irons, it is enriched with concentrated nutrients. So, you will get a faster result.

Ironite improves the soil quality so that your lawn requires less water. However, you need to be careful while applying its liquid form. It can stain your concrete! Read here when to apply Milorganite on the other hand.

  • Iron Concentration

After a proper soil test, you can determine whether your lawn has a deficiency of iron and other nutrients.

If the shortage of iron is proven, your lawn will be better off with the Ironite. It has more iron than Milorganite slightly. So, your lawn will be green a lot faster.

  • For Soil Quality

Apply Miloganite if getting a slow but steady result works for you. Yes, it works by improving your lawn soil and you will get a long-term benefit out of it.

  • Harsh Chemical Agents

When it comes to Milorganite vs. Ironite, both of them contain some sort of heavy metals like lead and arsenic. But Ironite has such harsh chemical agents more. That’s why you should never apply Ironite without doing a soil test. Applying it unnecessarily will do harm to your garden and lawn.

  • Consitent & Long-term Results

If you feed your lawn grass through their roots, you will get a more consistent result and it will have a long-term impact on your lawn. Milorganite works that way and over time, you will get a healthy lawn.

On the other hand, applying Ironite too much more frequently will definitely harm your lawn. I have seen some people have ruined their lawn applying too much of it.

Imagine the liquid Ironite as an energy drink that will give your body a quick energy boost. But that feeling fades away quickly and consuming too much of it is definitely bad for your health.

Likewise, you can compare Milorganite with milk. It’s good for your health over the longer period but you have to be patient to see the results.

  • Milorganite Is More Eco-friendly

Yes, both of them are helpful to have a green and lush lawn. But as you know, over applying the Ironite may bring negative results – you need to have your math right.

If you use the liquid version of it, try to mix it with a natural dye so that you can identify easily where you have applied it on your lawn.

Milorganite And Ironite: Be Safe Than Sorry


Ironite has both the urea nitrogen and Muriate of potash. Both of the ingredients can potentially burn if not used correctly. You can apply it maximum 10 times a year but the recommended usage is 4 times.

For 100 square feet of your yard/lawn, you should not use more than 1 pound. And you should immediately water it afterward thoroughly.

If it’s springtime, don’t fertilize your lawn too soon. That’s how you will ruin your beloved lawn.


If you apply it too soon, your lawn grass will have rapid growth but there will be little to no growth for the roots. Your lawn grass needs strong roots to withstand the drought conditions coming one way or another.

The right time to apply Miloganite with any fertilizer is mid-May. Only then your lawn grass will have deep and strong roots.

The worst thing you can do is not following the instructions correctly when applying it.

The same goes for the Milorganite too. You must apply it before you fully understand what you are doing. Do not try to skip the instructions even if you are an experienced gardener.

Frequently Asked Questions (FAQ

Which is better Milorganite or Ironite?

If you need something natural to make your lawn green over a short period of time, Milorganite is your best bet. It does not contain any harmful chemicals like the Ironite does.

What will Milorganite do for my lawn?

If you need a long-lasting and consistent positive result for your lawn, it needs something like this.

It’s a slow-release nitrogen fertilizer that you can apply directly on your lawn or when spreading seed. Being totally natural, it is very safe to use.

Does Ironite contain arsenic?

Yes. It contains not only arsenic but also leads too! And it is confirmed by a study lead by EPA. The study has found that Ironite contains more arsenic than any fertilizer!

Will Milorganite kill weeds?

No, it won’t. It does not have any added herbicides to kill weeds or pesticides. It’s simply a natural fertilizer to help your lawn grass grows.

Is Ironite pet safe?

Yes, if it is applied as per the instruction on the label. However, you should not allow your pet or any kids in the yard until the treated area is fully dried.

Can you put too much Milorganite on your lawn?

Nope. You should always follow the instructions where it will tell you the exact ratio considering the lawn area. Overdoing anything will bring nothing but harm to your lawn.

Should I put Milorganite down before it rains?

You can but you have to make sure the excess the rainwater can’t wash the Milorganite away from your lawn. Rainfall is always good for your lawn!

Sum Up

Congratulations! You have come a long way and I believe you have got the main distinction points of Ironite vs. Milorganite.

If you are still wondering which is better Ironite or Milorganite, I would say Milorganite (since I am an organic kind of guy).

But, Ironite for lawns is not always a bad idea and the choice is yours to make. Just don’t overdo anything to your lawn and read instructions carefully before you apply any fertilizer.

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1 thought on “Ironite Vs. Milorganite: Key Distinguishing Points & WARNING!”

  1. Can I apply both Miloganite and Ironite on the same day or what is the recommended timeframe between both applications?

    Also any temperature restrictions?

    Thank you LIND

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