Frequently Asked Questions

What is Milorganite?

Milorganite is composed of heat-dried microbes that have digested the organic material in wastewater. Milorganite is manufactured by the Milwaukee Metropolitan Sewerage District. The District captures waste water from the metropolitan Milwaukee area, including local industries such as MillerCoors. This water is then treated with microbes to digest nutrients that are found in it. Cleaned water is then returned to Lake Michigan. The resulting microbes are then dried, becoming Milorganite fertilizers. The Milorganite program is one of the world’s largest recycling efforts.

My dog ate Milorganite what should I do?

Milorganite is not toxic if eaten, and your dog is not facing a “life threatening” crisis that requires medical care or emergency stomach pumping. The manufacturing process of Milorganite destroys pathogens, eating any product off of surfaces containing pathogens (such as soil or turf) may introduce a source of pathogen infection. How much discomfort your dog has will depend on how much Milorganite was consumed.  Continue reading...

How soon after applying Milorganite can my dog return to the lawn?

Some dogs are attracted to the odor of Milorganite, and may lead to their rolling on freshly fertilized surfaces, eating the product off the lawn, or eating directly from open bags. Remember to store Milorganite out of the reach of dogs. After spreading, monitor your dog to determine their interest in the product.  To reduce the attraction we recommend watering your lawn after application and keeping your dog off the lawn for 24 hours. Continue reading...  

Is it poop in a bag?

A common misconception is that Milorganite is “poop in bag”, when in fact Milorganite is actually composed of heat dried microbes. These “bugs” eat the solid materials in the wastewater, die off and are heat-dried between 900⁰F and 1200⁰F. This extreme heat and dryness kills pathogens. Thus Milorganite is really heat-dried bugs, and is safe for use on your lawn, trees, shrubs, flowers, and vegetables. Milorganite is regulated by the EPA and complies with the most stringent requirement, for more information on Milorganite’s Safety.


What is my spreader setting?

While settings for the most widely used spreaders on the market are printed on the Milorganite bag, it is not possible to test the setting for every available spreader. We have included Spreader Settings for the spreaders which have been tested and step-by-step Spreader Calibration Instructions to determine the proper setting for spreaders that are not listed on the Milorganite bag.

Is it safe?

Your safety is an extremely important consideration in the production of Milorganite.  Milorganite meets the most stringent criteria imposed on any fertilizer product for health, safety and environmental concerns.  Milorganite complies with all federal and local limits, which allows Milorganite to be used with confidence for all of your fertilizing needs, including grass, trees, shrubs, flowers, and vegetables.  For more information visit our Safety page.

Does Milorganite contain heavy metals?

Milorganite and all other fertilizers, both organic and synthetic, contain some heavy metals. Heavy metals like cadmium, copper and zinc are naturally occurring in our everyday environment. Several of these metals are actually micronutrients that are needed in small amounts for plants to grow and reproduce. The concern with heavy metals in fertilizer is keeping their concentrations under limits deemed safe by EPA regulators. Continue Reading...

What does the 5-2-0 on the bag mean?

The 5-2-0 guarantees that Milorganite contains at least 5% Nitrogen, 2% Phosphorous and 0% Potassium by weight.

Can I use Milorganite for my vegetable garden?

Yes, Milorganite is an excellent and safe fertilizer for all plants that grow outdoors, including vegetables. The slow-release organic nitrogen feeds plants evenly and gradually, without interfering with flowering and fruit development.  This nurtures the roots, which in turn develop more robust yields.  Other fertilizers force unnecessary top growth, which makes for skinny plants with reduced yields.

Where can I buy Milorganite?

Homeowners can find Milorganite at most lawn and garden stores across the country (it is America's #1 organic nitrogen fertilizer). Our store locator can help find a store near you. Retailers and Landscape Professionals can get Milorganite from our extensive distributor network, often the same supplier for your other lawn and garden products.

Is Milorganite approved for use on commercially grown USDA organic certified crops?

No, Milorganite is not approved for use on commercially grown USDA certified organic crops.  This certification is for produce sold as “certified organic” in retail outlets.

What is the difference between organic and "regular" fertilizers?

Synthetic fertilizers are “fast food”, best known for being fast-acting once they are watered in.  Synthetics are manufactured chemically with high burn and leaching potential. Organic fertilizers are “slow food” and obtain their nutrients from natural sources.  Organic fertilizers build the soil structure, feeding plants slowly over a longer period of time.  Organic fertilizers contain no chemical salts, which can burn vegetation.

What is organic lawn care?

The primary tenet for an organic lawn care program is to work with nature rather than against it.  A organic lawn care strategy reduces the pollution sent into the atmosphere, the nutrient run-off into waterways, the waste placed into landfills, and the amount of inorganic chemicals used that disturb the natural order of life in your soil. By building healthy soil many of the problems with your lawn can be solved.  Learn more…

Does Milorganite need to be watered in immediately after application?

No. It is not necessary to water in Milorganite immediately after application.  Milorganite will stay on the soil until rain or irrigation activates soil microbes that break it down into nutrients. Watering in Milorganite will ensure that the fertilizer achieves soil contact earlier and speed up the fertilizing process.

Can Milorganite be applied in the summer or during drought?

YES.  Milorganite does not contain any salts so it can be applied during summer or drought conditions and will not burn. You can apply anytime, and the Milorganite will be ready to work when moisture arrives later making it ideal for areas with water restrictions.

Can Milorganite be applied to my wet lawn?

Yes. Milorganite does not contain any salts so it can be used on a wet lawn.  Milorganite will not burn your lawn.

Is it true that Milorganite will keep deer away?

Research conducted at the University of Georgia suggests that Milorganite is a useful tool in repelling deer from grazing on food plots and ornamental plantings. Research indicates Milorganite's odor is effective in keeping deer from browsing plantings up to 5 weeks. Spread Milorganite around your plantings to deter deer. The study used an application rate of one half cup per plant and concluded that reduction of plant damage may improve if Milorganite is reapplied at day 14.

Can Milorganite be used in combination with other fertilizers (and pesticides)?

Yes. Milorganite can be used as a complete lawn fertility program or with other products as part of your program. When you use Milorganite as part of an overall program, do not over-apply nitrogen fertilizer.

Does Milorganite kill weeds?

No. Milorganite is strictly a fertilizer. However, a thick, healthy lawn will choke out existing weeds and help prevent weeds from germinating seedlings.

Can Milorganite be applied with Lime?

Yes. The two have no interaction and can be applied at the same time, but only if a soil test indicates the need for lime. Lime is the most common way to change the pH of soil. Soil pH is a measure of soil alkalinity or acidity. A soil is acidic if it has a pH below 7.0 (neutral). You may need to add lime to your soil if a soil test indicates a pH level below the optimum of 6.0 or 7.0. Working towards achieving an ideal pH level will help bring the soil into balance and allow for optimum nutrient uptake.

Can I apply Milorganite on top of mulch?

Yes, the Milorganite will work its way down into the soil.  If you have time and the bed size is manageable, you may prefer to remove the mulch or rake it back from the plants a few inches, fertilize, and then reapply the mulch. This will immediately place the fertilizer in direct contact with the soil.

Does Milorganite contain grass seed?

No, however mixing grass seed with Milorganite makes it easier to accurately spread seed, especially small-seeded species like bentgrass and bermudagrass.  The standard Milorganite:seed mixing ratio is 4:1 by weight.  When mixing seed and Milorganite, decrease the rate of Milorganite applied as straight fertilizer to avoid over-fertilization.

Can I apply a grub control at the same time as Milorganite?

If the grub control product contains any fertilizer in it, we do NOT recommend applying an application of Milorganite.  You do not want to risk over fertilizing your lawn.  If the grub control product DOES NOT contain any fertilizer, you can apply Milorganite.

When can Milorganite be applied?

Milorganite can be applied any time during the growing season.  However, for best results we recommend four annual applications on your lawn; please visit our lawn application page for your regions fertilizing schedule and rates.  Please visit our application rate pages for flowers, vegetables, fruits, shrubs & trees.


How far away should you fertilize from a waterway?

When fertilizing near a body of water do not fertilize within 10 feet of any waterway (ocean, lakes, streams, ponds).  For more tips on fertilizing responsibility near waterways visit here.

What about Milorganite's Phosphorous?

The slow-moving phosphorus in Milorganite stays in the soil for the plants to use. University tests in the soil of Florida show that Milorganite’s phosphorus is available to the plants but does not move into the groundwater.

Does Milorganite contain pharmaceuticals?

Milorganite, like manures and other organic fertilizers, contains micro-levels of pharmaceuticals as well as household and personal care products. Milorganite is actively  monitored for a host of compounds that the EPA has ruled as being hazardous, to ensure consumer safety.  Continue Reading...

Milorganite's Safety Data Sheet (SDS)

Milorganite is registered for sale in all 50 states and meets all federal and state requirements. View Milorganite's Safety Data Sheet (SDS).