What Is Milorganite? Why I Apply It To My Lawn?

Many people, especially the ones concerned with lawn care, are asking these questions: what is milorganite? when, why, and how to apply it to your lawn? in this article, we will answer all the questions above and I will share with you my experience applying this lawn fertilizing product.

To start with, Milorganite is a fertilizer made from treated sewage sludge in Milwaukee, Wisc. Due to its 85 percent organic ingredients, it is classified as a natural fertilizer, even if the U.S. Department of Agriculture does not permit its use in certified organic agricultural production. 

Also, it is not a compost. As opposed to chemical fertilizers, it releases nutrients bit by bit, which means it may be a better choice for banning excess nutrients draining into groundwater and waterways.

Manufacturing Process

The treatment process that relies on sewage adds oxygen and microbes to wastewater gathered from the Milwaukee area. A clumping agent is added after the microbes consume the nutrients in the sludge.

The following step is pressing the material and then drying it with high heat, which kills pathogens. And as a result, you get a pelleted, dried fertilizer.

What Is Milorganite


When it comes to the composition of the fertilizer, it is listed in ratios of phosphorus, potassium, and NPK — nitrogen. Milorganite holds 2 percent phosphorus, .32 percent potassium, and 5 percent nitrogen.

Also, it contains 4 percent iron, .58 percent, and .68 percent magnesium, the secondary nutrients calcium, as well as 2.1 percent sulfur. And other traces of micronutrients, like chloride, boron zinc, and copper.

How It Works

What Is Milorganite? Why I Apply It To My Lawn? 1

Milorganite materials are 85 percent organic. Organic materials are known as slow-release fertilizers because they release nutrients to plants over time.

Organic ingredients are much better because the over-application of chemical fertilizers can burn plants.

Rather than an unhealthy and a chemical boost, over a period of two to three months, microbes in the soil digest the nutrients in Milorganite and deliver them to plants.

This means that the nutrients stay in the soil until conditions are optimal for plants to take them up during the growing season.

What Is Milorganite? Why I Apply It To My Lawn? 2


To fertilize grassy, large areas, many sports fields, golf courses and parks, use Milorganite. And because it doesn’t contain anything that will burn grass, it can be used anytime during the growing season.

Additionally, rainfall, drought, and high temperatures do not prevent the Milorganite application. Bear in mind that it normally does not require watering, however, during the dry season, watering will push the material into the soil faster.

What Is Milorganite? Why I Apply It To My Lawn? 3


The Environmental Protection Agency confirms that Milorganite is approved for home gardening use. It is not toxic to pets or humans because its main source is wastewater, however, it may have some traces of pharmaceuticals.

It is likely to cause stomach upset and vomiting if a handful or more is eaten due to its relatively high iron content. Make sure to keep all fertilizers away from pets and children.

Why I Apply Milorganite To My Lawn? (My Experience)

One of the reasons why I’ve liked using milorganite over the past couple years, is that it really helps to build our soil, so depending on what kind of soil you have maybe you have a clay soil, maybe you have a really sandy soil there’s not a lot of nutrients in there and this is gonna help us over time.

It’s going to take some time but it is going to help us to build our soil build the natural activity in the soil the microbes, I’ve just noticed over time that this has helped to build my soil make things a little bit healthier overall, and that’s always what we’re going for.

why i apply milorganite to my lawn

Finally, I have one more thing to mention about iron, It is a really good way to help the grass green up a little bit more without pushing some growth on it.

So this fertilizer contains a little bit of iron as well and I’ll probably be doing some iron applications alone in addition to this fertilizer.

So normally when I apply this fertilizer maybe you get a little bit of rain afterwards, it’s normally when I start to see a little bit of the green-up quickly, and that’s mainly from the iron there so you can add iron to your yard without using a fertilizer you can do it in a standalone application, but the little bit of iron is just going to help us get a little bit extra green, It helps things turn a little bit more of a blue-green and it just helps the yard to look really nice.

What Is Milorganite? Why I Apply It To My Lawn? 4


Milorganite and all the other types of fertilizers have their advantages also as their limits.

Organic lawn fertilizers play an important role in returning organic carbon to the soil, however, their nutrients are less obtainable or too available at an instant of the crop cycle wherever it’s less required by the plant.

One fertilizing product alone can’t make sure that the crops would grow to its most genetic potential. The balance between fertilizing products is vital because of the balance between the essential plant nutrients.