Bags of Milorganite and Milorganite grey trucker hat



Made in Milwaukee Since 1926

Milorganite® fertilizer is manufactured by the Milwaukee Metropolitan Sewerage District (MMSD). MMSD captures wastewater from the metropolitan Milwaukee area, and using large-scale processes that mimic nature, microbes digest the nutrients found in the water. The cleaned water is returned to Lake Michigan while the microbes are kiln-dried into small pellets. Milorganite® is actually a bag of dried microbes (not poop)!

The production of Milorganite® is one of the nation’s oldest recycling efforts. For more than 95 years, we've safely recycled these nutrient-rich microbes into a slow-release fertilizer that works wonders for lawns, gardens, flowers trees, and shrubs. Milorganite® stands for "Milwaukee Organic Nitrogen".

How is Milorganite® Made?

Wastewater enters the Jones Island water reclamation facility where all solid materials such as sand, boards, shop rags, plastic, and debris are first removed. Microbes are added to the water—the activation process—and oxygen is bubbled through the water to create the ideal environment for the microbes to digest the nutrients in the water.

The microbes die after they consume all of the nutrients. Binding agents are added to the water causing the microbes to clump together and settle to the bottom of the undisturbed water in sedimentation tanks. After everything has settled the cleaned water is returned to Lake Michigan and the microbe clumps are sent on for dewatering and drying.

Moisture is first squeezed out of the clumps using belt presses resulting in something similar to wet cardboard. The semi-solid material moves on to one of 12 rotary kiln driers heated to 900–1200 ⁰F which heats the Milorganite to an internal temperature of 176°F. The extreme heat kills pathogens.

Milorganite is analyzed for at least 20 parameters every day to comply with all applicable safety guidelines for protecting human health and the environment. After passing all tests, it’s ready to be packaged and shipped throughout the United States.

Since 1926, Milorganite® production has diverted over 10 billion lbs. of waste from landfills.

What is Milorganite® Fertilizer?

Milorganite is an all-purpose, slow-release nitrogen fertilizer that safely feeds your lawn, flowers, vegetables, shrubs, and trees for up to 8-10 weeks after application. Milorganite fertilizer is made using large-scale processes that mimic nature; microbes (bugs) digest the nutrients found in the wastewater and are kiln-dried into small pellets. A bag of Milorganite is composed of heat-dried microbes that have digested the organic matter in wastewater. ​​​​​​​

Milorganite® Customer Reviews

Customers across the United States share their Milorganite® stories with us of their beautiful lawns and gardens. You can see our customer testimonials on the Milorganite® social media channels and website.

Are you a fan of Milorganite®? Please share your Milorganite® story with an image or video. To show our appreciation for your support of Milorganite® we will send you a Milorganite® sticker and you can select from a t-shirt, hat, or rain gauge. Thank you, for being a loyal customer and sharing your Milorgnaite® story with us!


Individuals playing volleyball in Milorganite tshirts