When to Use Milorganite

When to Use Milorganite On Your Lawn for Best Results

Milorganite, an organic nitrogen fertilizer, is a product that you’re likely to consider using on your lawn. That’s because you can apply it without risk of burning your grass. Also, it contains a iron, which means when you apply Milorganite it will help grass achieve a beautiful dark green color. But you may wonder when to use Milorganite on your lawn to achieve the best outcome.

In this article I’ll explain the best schedule for Milorganite application so you can maximize the benefit of this incredible organic fertilizer without wasting money by applying it too frequently.

Trust and Accuracy Information

This article was last updated on by Lawn Chick Owner Sarah Jameson
Article content reviewed for accuracy by Certified Horticulturist Nicole Forsyth, M.S.

Jump Right to the Milorganite Schedule

I’ve got lots of good info in this article and hope you read the whole thing, but if you’re just here for a Milorganite application schedule, I’ve got you … you can skip ahead right here:

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What is Milorganite?


Milorganite is an organic fertilizer for lawns and gardens which is manufactured by the Milwaukee Metropolitan Sewerage District.

It’s produced through the treatment of wastewater with microbes. After the end of the process, the clean water that is separated from the product is released into Lake Michigan. The product, which is the microbes left over, are heat-dried, which makes them safe to apply and free of pathogens. This is when they become Milorganite, the fertilizer millions of homeowners around the country apply to their lawn.

Thank you, kind people of Milwaukee!

It’s common for gardeners to be concerned with Milorganite’s safety. After all, it’s manufactured from wastewater. Luckily, there’s nothing to worry about, and in fact the ability to safely reuse wastewater in this way is pretty revolutionary.

The meticulous process of production involves the microbes being dried under tremendously high temperatures of between 900 and 1,200 degrees Fahrenheit. This dries out the microbes, destroying all of the pathogens, making it one of the safest organic fertilizers to use on your lawn or in your garden.

After the drying process, there is a careful testing process to make absolutely certain that Milorganite is safe to use and won’t cause any human health concerns. It is held to the standards of the U.S. Environmental Protection Agency.

Milorganite Application Rate and Schedule

The manufacturer of Milorganite fertilizer recommends specific application rates and schedules. It’s important to be aware of these, as if you don’t abide by the instructions, you’re unlikely to achieve the best possible results for your property.

Milorganite Application Schedule

When deciding on an application schedule and finding out how much Milorganite fertilizer you should apply, you must consider the species of grass you have and where you live.

One general rule of thumb is that you should use a single 32-pound bag for every 2,500 square feet of lawn.

How Many Bags of Milorganite per Acre?

This table is based on the manufacturer’s recommended application rate of 2,500 square feet per bag.

Yard SizeBags of Milorganite*
2,500 sq feet1
1/4 acre5
1/3 acre6
1/2 acre9
2/3 acre12
3/4 acre13
1 acre18
*Recommended bags rounded up to the nearest whole number

Keep in mind that if you have a 1/3 acre property, your house, driveway, and gardens occupy some of your lot’s square footage, so you probably won’t need 6 full bags for your property.

How Many Times per Year Should You Apply Milorganite?

Generally, you should fertilize four times annually. If you choose to fertilize only once a year, though, early fall is the most appropriate time as you’ll provide your lawn with plenty of nutrients to bounce back strong after a long winter.

Now let’s get a little more granular about when to use Milorganite in different parts of the country and on different types of lawn.

RECOMMENDED: The Fall Lawn Fertilizers I Recommend

Warm-Season Grasses in the South

When to Use Milorganite in the South

If you live in the south it’s likely that you have a warm-season grass such as Zoysia, Bermuda, Bahia, St. Augustine, or Centipedegrass.

In this case you will want to fertilize with Milorganite four times every year for best results.

The exception for southern lawns is if you have Bahia or Centipedegrass.

If your lawn is primarily either one of these grass species, you should fertilize in the spring and summer only. You shouldn’t do an application in the fall, as you could run into problems with winterkill in your yard if you do.

You’ll know when to do your spring fertilizing with Milorganite in the south once the last frost has passed and your grass starts to get green and appears to be growing.

When to Use Milorganite on Warm Season Grasses

It’s generally best to apply Milorganite fertilizer to warm-season grass at the following times of year:

  • Easter (this should be after the turf comes out of dormancy): The application rate at this time is 32 pounds per 2,500 square feet.
  • Memorial Day (the end of May): The application rate at this time is 32 pounds per 2,500 square feet.
  • Labor Day: The application rate at this time is 32 pounds per 2,500 square feet.
  • Early October (alternatively, when you do fall overseeding): 32 pounds per 2,500 square feet.

The Spreader I Use & Recommend

I’ve owned and used a number of different broadcast spreaders, and if you want the best one available, I recommend The Andersons Yard Star spreader. It is American made, can hold 50 pounds of material, rolls smoothly and easily, and is the most accurate spreader I’ve ever used.

Cool-Season Grasses in the North

Examples of cool-season grasses are Perennial Ryegrass, Kentucky Bluegrass, and Fescue. If your lawn is in the Northeastern US, pacific northwest, or northern half of the midwestern United States it’s likely that you have cool season grasses, which you should fertilize these grasses four times annually.

Milorganite Schedule in Northern Climates

When to Use Milorganite on Cool Season Grasses

The following are generally the most effective times to fertilize your cool-season lawn with Milorganite:

  • Memorial Day (the end of May): The application rate is 32 pounds per 2,500 square feet.
  • July 4: The application rate is 32 pounds per 2,500 square feet.
  • Labor Day: The application rate is 32 pounds per 2,500 square feet.
  • Thanksgiving (second half of November): The application rate is 32 pounds per 2,500 square feet.

Tips for Fertilizing New Lawns with Milorganite Fertilizer

If you want to feed a new lawn with Milorganite, mix it into the top couple of inches of the soil prior to applying your seed.

When to Use Milorganite for New Lawns

After your grass seedlings germinate and you’ve mowed your lawn three times, apply two bags (32 pounds each) for every 2,500 square feet of grass. This is 2x the recommended rate for established lawns, but will really give your young grass the nutrients they need to thrive.

After this, follow the application schedule for your grass type / region I outlined above, but continue at 2x the standard application rate for the first year (64 pounds / 2,500 square feet).

Milorganite Fertilizer is a Great Choice for Lush, Green Grass

If you’re looking for a magic bullet that will transform your lawn to make it the envy of your neighbors, give Milorganite a try. It won’t magically cure all of the underlying issues in your lawn (weeds, ants, grubs, and other pests)

It’s this organic nitrogen fertilizer’s high iron content is what makes it so incredibly effective at transforming the look of your lawn. It will feed your grass, and green up your yard without burning your grass.

It’s one of my favorite lawn fertilizers, and you now have all the information you need about how much to apply and when to apply Milorganite to feed your lawn with this organic, sustainable product.

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Sarah Jameson’s blog, Lawn Chick, is read by over 2 million homeowners each year and she is regularly cited as an expert source of lawn care knowledge by major publications. Her goal is to meet you where you are, and help you achieve a yard you’ll be proud of. Ready to take the next step toward improving your lawn? Grab her free lawn care cheat-sheet: What to Do When - Take the Guesswork Out of Lawn Care, or upgrade your garage by browsing her favorite DIY lawn care products.

24 thoughts on “When to Use Milorganite On Your Lawn for Best Results

  1. Catherine Evans

    Can I Use moilorganite after using another fertilizer. I have brown spots in my centipede lawn put seeds and fertilizer out 2 weeks ago can I use milorganite

    • Yes, Catherine – Milorganite is a slow release fertilizer so it won’t burn your lawn. You might not need to apply it just yet, but there shouldn’t be a problem if you apply Milorganite a few weeks after application of a different fertilizer. Good luck!

    • Hi, Robert!

      Definitely – that’s a good schedule to follow for the first two applications.

      For southern lawns with warm season grasses I recommend spreading Milorganite around Easter and again around Memorial Day. For northern lawns with cool season grasses I recommend initial application around Memorial Day and a follow-up application around July 4th. Most lawns will be all set at that point until early fall (Labor Day) when you can do a third application.

      When you start for the year really depends on your local weather, but I do like to do the second application about 5 weeks after initial treatment, which will carry your lawn through the summer in most cases.

      Thanks for the comment!

  2. Kimberly

    Hi! I have a mix of grass – Bermuda and St Augustine in north Texas. With housing construction in my community, I have a surplus of crabgrass, and several other weeds that I don’t know their names 😔 Will Miloganite work for my grass? I have had a beautiful lawn for so many years until this construction in the cattle land. Very frustrating

    • Hi, Kimberly!

      Yes – Milorganite is a great fertilizer for pretty much every type of grass and plant. It’s slow-release, organic, and has some iron to help with green-up. It should work great for your Bermuda / St. Augustine lawn.

      Sorry to hear about the damage from construction. I have a bunch of articles with tips for how to deal with different types of weeds which you can browse here. Hopefully some of that information helps – good luck with your lawn this year!

  3. Corina

    Hello, I had Turkey manure put on yard a week ago. Should I wait before putting Milorganite?
    If so, how long?

    Thank you

    • Eugene

      Can I combine milorganite with PGF complete or PGF Balanced? I put milorganite down last week. I wanted to use PGF complete after Easter. So I plan to use PGF in April and late May and then Milorganite in September.

      • Hey, Eugene –

        Yes – that timing should be ok since Milorganite is slow-release and non-burning. I wouldn’t recommend putting them both down the same day, but sounds like you’ve got a few weeks between the applications so that should get you an amazing green up between Easter and Memorial Day. If it were me, I’d err a bit on the light side with your PGF Complete in this case.

  4. Will

    I’m a bit confused on the coverage recommendations for Morganite. 18 bags for an acre would run more than $500. That price x4 applications seems like a lot of material AND money. Can that be right?

    • Hey, Will!

      Great question. There are 43,560 square feet in an acre, so technically you’re looking at just south of 17.5 bags at 2,500 square feet/bag. That’s still a lot, but most properties have a house, driveway, garage, gardens, and other areas which eat into that square footage total. I have an article with links to some free online tools to help you measure your lawn size (you can read that right here). This can help you find out exactly how much product you’ll need for your property. I recommend breaking your lawn out into sections (front lawn, side lawn, back lawn), and writing out how many square feet are in each unit, then going from there. This will not only tell you how much product you need for each part of your lawn, it will help you spread the product more accurately and ensure that you don’t get half-way through and run out because you applied too much.

      I will also say that depending upon where you live you may be able to find Milorganite on sale locally for under $20/bag. I’ve had good luck at Ace – here’s that link to order online for curbside or local delivery. At this time of the year it might be tough to find it, but if you are on your game and look early next season you can grab what you need at a discount while there’s still snow on the ground.

      If your budget is tight shopping early and locally at Ace Hardware or a similar store is my first tip, and my next tip is to break your lawn out into sub-sections and apply Milorganite only to the most important parts of your lawn. This way you get the results you want where it matters most, and you can judge the difference between fertilized and unfertilized sections of your lawn for yourself and decide how much you want to invest next year.

      Good luck!

    • Sure, Robert –

      Shouldn’t damage your seed/seedlings! I typically use a quick-release starter fertilizer when I seed and follow that up 4-6 weeks after germination with Milorganite. Helps sustain the seedlings as they establish.

      Good luck!

  5. Danny combs

    Live in southeast tennesse.. have tall fesque . .. overseeding with Scott’s sun shade fesque.. purchased milo.. can I apply with the overseeding this fall?? Never have used milo!!! Thanks for your help

  6. Tommy H

    We have some dead spots in our yard, St. Augustine grass. A lot of the dead spots are around the sidewalks, but some in the middle of the yard. Is it best to spread milorganite on the dead spots after mowing? Then, at what point should I re-seed the dead spots with the St. Augustine seed? Thanks for your help! We are in coastal Georgia.

    • Hey, Tommy!

      If the dead spots are around sidewalks it sounds like it’s probably an issue of foot traffic and/or compact soil killing off your St. Augustine. I’d try aerating the soil in those sections of your lawn before you lay down seed, as areas near sidewalks (especially corners and curves where people like to take shortcuts) tend to get compact from extra footsteps.

      An easy and cheap way to do small areas like this is to just use an iron garden rake to loosen the top few inches of soil. After this is done I’d re-seed that area and cover with a thin (1/4″) layer of compost to protect the seed and keep it moist. You can apply Milorganite or a starter fertilizer when you plant the seed. If you use a starter fertilizer, I’d follow it up with Milorganite 4-6 weeks later. Keep the seed moist by watering morning and afternoon for a few weeks, and once your seed has germinated, try to transition from frequent light watering to less frequent (daily) deep watering to encourage the seedlings to develop deeper roots as they seek out the moisture deeper in the soil. This will help your lawn become more resilient in these areas.

      Since you’re in Georgia you’ll probably want to wait until the spring to tackle this at this point.

      Hope this helps!

  7. Mike

    1. There’s no potassium in Milorganite. Does this genrally cause issues? If so, what would you suggest for potassium supplementation?

    2. Can I use liquid iron in addition to milorganite (at least until it starts to work and makes things green again)?

    • Hey, Mike

      The absence of potassium doesn’t really cause issues in most lawns, but if you’d like to supplement I’d recommend a 15-0-15 liquid fertilizer like the ones I recommend on this page. They work great, and will complement the slow-release Milorganite nicely. And yes, you can apply liquid iron at the same time as the Milorganite or the 15-0-15 for that burst of green you’re looking for. Good luck!

  8. Jeff Kaibel

    I have used Scott’s almost exclusively on my yard (Fescue) for a number of years, but I like to mix in an occasional Milorganite application each year. I’m in the Midwest (MO), so I generally do my first application of Scott’s in mid-March, and a follow-up Weed & Feed in mid- to late-April. I’m thinking with that schedule that I can apply Milorganite around Memorial Day, then come back with my summer application of Scott’s in mid-July. Does that seem appropriate to you ?


    • Hey, Jeff!

      Yes, the nice thing about Milorganite is you can work it into your normal program in a number of ways without worrying about over-fertilizing because it’s a slow release product. You should be just fine applying it around Memorial day with the schedule you outlined above, and you’ll probably love the impact the extra Iron from Milo will have to complement the Scott’s products. Good luck!

  9. Joe

    I live in Cleveland Ohio and have a company fertilize my lawn . I canceled the first and last application do to cost . The first application will be end of April instead of march. You said to apply milorganite Memorial Day cani apply it in march instead. If not as good as Memorial Day let me know.

    • Hey, Joe!

      Yes, you should be fine to apply it in March as long as your lawn is awake and has started to come out of dormancy. The timing is really location-dependent – a lot of cool-season lawns are still covered in snow during March!

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