Milky Spore Granules vs Powder

Milky Spore Granules vs Powder (which I recommend)

Milky spore is a very popular organic way to control lawn grubs in residential yards around the country. It’s a naturally occurring bacteria that helps to control Japanese beetle grubs, a common lawn pest which can wreak havoc on lawns and (at maturity) ornamental gardens. There are different products and forms of milky spore available to homeowners, each with different advantages and disadvantages. Today, I’ll be comparing milky spore granules vs powder to help you choose the best product for your lawn application.

Trust and Accuracy Information

This article was last updated on by Lawn Chick Owner Sarah Jameson
Article content reviewed for accuracy by Horticulturist Arthur Davidson, A.S.

Let me begin by explaining why I’m a big fan of using granular milky spore on my lawn.

My Experience Using Milky Spore on my Lawn

I’m an advocate because I’ve been a customer and have seen first-hand results using milky spore on my property.

While you won’t see immediate results in combatting a raging grub problem the way you might with a chemical insecticide, this is a sustainable way to manage grubs by adding a naturally occurring bacteria (which I love).

It allows you to target “bad actor” insects that are damaging your yard without nuking the entire population and harming beneficial insects.

The bacteria will build over time, and I recommend that homeowners apply this product three times annually over a two year period (spring, summer, and fall). After this initial investment, the bacteria population will remain in your soil for years. It can stand up to rainfall and other environmental factors and you don’t have to worry about runoff.

And most importantly, it’s an effective way to control most problematic grub populations and prevent the problems and damage they can cause (but it won’t work on some grub populations, like those found in Florida).

There are a few differences between the powder and granule versions of milky spore. The granular version is the original form of this product, and homeowners have used it for decades with great results. It’s the product I recommend.

Best Grub Control Product

The Grub Control I Use and Recommend

I’ve personally had great results with St. Gabriel’s Granular Milky Spore for lasting Japanese Beetle grub control. Apply it 3x annually for two years and will then enjoy ~20 years of worry-free protection from harmful grub infestations.

It’s a natural biological grub control method that is far safer than applying a dangerous insecticide. is reader supported. If you make a purchase after clicking a link, I may earn a commission at no additional cost to you.

What Is Milky Spore, Exactly?

Milky spore is a strain of bacteria called Bacillus popilliae that will control the population of Japanese beetle grubs in your lawn. As these grubs can do a lot of lawn damage, using milky spore is a great way of keeping your lawn healthy.

What is Milky Spore

There are many different pests that eat the Japanese beetle grub. So, when you get rid of the grubs, you’re cutting down on the chance of those pests coming onto your property.

Often, a robust grub population in your lawn will be evident not just through damaged grass, but also by the presence of moles, skunks, and other animals that come to eat the grubs and tear up your yard in the process.

Milky Spore works by offering a harmful food source to the grubs you want to remove.

Japanese beetle grubs will eat milky spore, and it will make them sick so that they eventually die off.

Over time and as you apply milky spore several times, the bacteria will eventually get established in your soil, making it an inhospitable environment for the grubs you don’t want.

As an organic solvent, milky spore is much less harmful than chemical-based insecticides/pesticides. This makes it a great choice for those who want to be eco-friendly in their lawn care and gardening practices.

How Safe Is Milky Spore?

Sometimes when we hear bacteria, we worry about infections and other health risks – so how safe is Milky Spore really?

Well, it’s important to remember that bacteria and fungi make up a huge part of your soil’s microbiome and are actually critical pieces of your yard’s ecosystem, working symbiotically with your grass.

Milky spore is safe to use on your lawn. This bacteria won’t hurt most helpful organisms, and shouldn’t pose any health risk to you or your 2-legged or 4-legged family members when applied as directed.

How Safe is Milky Spore

Keeping your lawn safe for pets, kids, family, and guests is very important, and milky spore is a great solution with almost no toxicity to humans.

One Caveat

When applying milky spore, there is a slight chance of irritation if the powder makes contact with your eyes or skin. This is true of most products you apply to your lawn, and why I always recommend homeowners do their applications on a calm day, and wear gloves, long sleeves and pants, and PPE (safety glasses, a mask or respirator).

Even “safe” products can irritate your body, and we all have plenty of PPE left over from the pandemic – so use it!

While milky spore doesn’t pose any serious health risks, I still recommend being cautious.

Why Should You Use Milky Spore On Your Lawn?

There are a few different reasons you should use milky spore on your lawn.

A Cost Effective Option

Beyond the fact that it’s eco-friendly, it’s also wallet-friendly.

In fact, when compared to annual applications of the leading grub insecticide on the market, I calculated that Milky Spore is 62.86% cheaper ($423.34 vs $1,139.80) over the course of 20 years. If you’re going to be in your home for 8 years or more, it’s going to save you money to go with 6 applications of Milky Spore over 2-years vs the annual applications of a market-leading insecticide.

An Eco-Friendly Choice

It’s an ec0-friendly way of controlling Japanese beetle grub populations in the soil, and it won’t harm any beneficial organisms. I explain this more completely in this article comparing it to a popular insecticide.

In fact, it helps create a healthy environment for beneficial insects, such as earthworms and ladybugs.

Why Should I Use Milky Spore on My Lawn

It’s Easy to Apply

It’s easy to use milky spore and if you go with the lawn-spreader bag, it’s easy to toss in your fertilizer spreader and distribute the product across your lawn.

Controls Other Lawn Pests by Limiting Their Food Source

Another great benefit of using milky spore is that it helps keep moles away. That’s because Japanese beetle grubs play a large part in this animal’s diet.

If you control those grub populations with milky spore, you’re much less likely to end up with moles tunneling through your lawn and leaving unsightly lumps and big dirt mounds throughout your yard.

You don’t have to buy expensive mole traps or hire a pest control company – just close the pantry!

Comparing Milky Spore Granules vs Powder

You can find milky spore products in either granule or powder form, so which should you be buying?

What are The Options for Milky Spore Application

While granules have been around much longer, the absorption rate for powdered milky spore is much higher, so depending upon the size of your lawn, one may work better for you than the other.

Granular Milky Spore

With granular milky spore, you get the best chance of a controlled and even application of the bacteria to your lawn.

It’s formulated so that it will stay in place and won’t spread to other areas of your property, and it’s less dusty to apply it (which, let’s face it, is an important consideration).

Powdered Milky Spore

The powdered version of milky spore is a little bit trickier to distribute, as wind or heavy rain can blow or wash it away.

However, as powdered milky spore works into the soil more quickly, you might see results more quickly.

My Advice

Making your decision on which version of milky spore to use on your property really comes down to the size of your property in my experience.

For small properties, you can use powder with good results, but for larger properties you’re going to want to go with a granular application.

Personally, I use the granular version in my fertilizer spreader and I’ve been very satisfied with the application and the results.

What Are The Pros And Cons Of Granular Milky Spore Products?

Milky spore granules have been the top pick for decades, and with good reason. This form of milky spore offers several advantages but also a few drawbacks.

  • The larger granules don’t wash away or blow away easily, so they’re great for a longer-term solution.
  • Granules are more resistant to hot or cold weather, so they’ll last longer on your lawn.
  • Granules can be easy to distribute as their size helps them fall straight to the ground where the product needs to be.
  • Granules are much slower to release the bacteria into the soil, so it may take longer to establish the milky spore in your lawn.
  • Granules cost more than powdered milky spore, so it may be more expensive to treat your lawn.
  • Using granules requires more applications overall to get the bacteria established.

Granular milky spore is definitely advantageous if you are willing to wait for long-term benefits. If you live somewhere with frequent rainfall and high winds, the granular option will be a better choice.

What Are The Pros And Cons Of Powdered Milky Spore Products?

Manufacturers developed powder versions of milky spore so that homeowners and gardeners could get faster grub-control results.

Let’s learn about the advantages and disadvantages of using powdered (instead of granular) milky spore.

  • Powdered milky spore requires fewer applications to get the same results.
  • Powdered versions of milky spore can be more easily distributed by hand and can be a great solution for smaller lawns.
  • The costs can be much less upfront as you won’t need as much of the powder to treat your lawn.
  • The powdered milky spore is more easily absorbed due to the finer particles.
  • Applying the powdered version of milky spore is more susceptible to the wind or rain blowing it away.
  • The powder needs to be applied in a dry atmosphere and won’t last as long as granules due to its smaller size.
  • It’s more difficult to establish long-term results with powdered milky spore.

Overall, the powder version of milky spore is a great solution if you want results quickly, have a small yard, or want to make a targeted application in a small area of your lawn.

For everyone else, I highly recommend that you go with granular milky spore instead.

What To Expect For The Longevity Of Milky Spore?

Milky spore is a fantastic product to remove the Japanese beetle grub from your lawn in as little as a year. However, you need to understand when to apply grub control (and how often you’ll need to do so) to get good results.

What to Expect for The Longevity of Milky Spore

If you use granular milky spore, you will need to treat your lawn and garden 3 times a year for 2 years. This is necessary to get the bacteria fully established in the soil. Once this happens, you’ll have incredible long term results.

Once you’ve properly established the bacteria in your soil, the amazing benefits of milky spore will last up to 20 years. When it comes time to reapply milky spore to your lawn years down the track, it won’t require the same volume of applications as the bacteria already has a good foothold … you’re basically re-invigorating the population.

While applying the powdered version can give you the same long-term results with fewer applications, there is more of a chance of it being affected by weather conditions due to its smaller particle size.

The key to long-term success with milky spore is getting the soil bacteria established properly. If you follow the product application instructions and apply it regularly, you will be sure to have a grub-free lawn for many years to come.

Either option offers an effective solution for removing the Japanese beetle grub and any associated pests so you can enjoy a healthy, vibrant lawn.

Keeping your soil healthy will make lawn maintenance easier for you.

Know Your Grub

I’ve had a few questions received via comment or by email from homeowners who did not see any result from using Milky Spore.

The problem? They lived in a part of the country where the Japanese Beetle isn’t present, so they were applying a product designed to target a grub they didn’t have in their yard.

The grub population they did have was not impacted at all, as this bacteria is not a food source for them.

So before you apply this or any product, it makes sense to do a little light research about the lawn grubs in your area or ask a pro at your local nursery and garden center. They’ll be able to confirm you’re good to go with this product.

For Lasting Lawn Health, I Recommend Regular Aeration (and possibly dethatching)

Beyond using milky spore, there are other natural steps you can take to minimize your grub populations.

One of these is cutting down on the moisture in your soil. While grass requires some water, standing water in your yard isn’t good and can lead to lots of problems.

I’ve found that regular (annual or bi-annual) aeration is helpful. And if your lawn grass spreads via rhizomes, dethatching your lawn may help as well.

Regular Aeration and Dethatching

These lawn care tasks are things you should do to your lawn to keep it healthy overall, and a thick healthy lawn is one of the best ways to limit the presence of lawn weeds and other lawn problems (like grubs).

Expert Perspective

The Lawn Chick editorial team regularly interviews industry experts to bring our readers the latest science and expert recommendations to complement our own hands-on lawn care experience. 

We Asked: Why is maintaining a thick, healthy lawn one of the best ways to prevent weeds naturally?

Will Answered:By maintaining a thick lawn, you’ll be able to limit the amount of ground available for these weeds to take hold, all while promoting the lawn of your dreams and avoiding unnecessary harsh chemicals or preventative herbicide applications.”

Will Seip, Expert Lawn Advisor at Sunday

Will Seip

Expert Lawn Advisor at Sunday

Born and raised just south of Buffalo, NY, it has been quite a journey for Will getting to explore warm-season grasses after having a hodgepodge of fescue, bluegrass and rye in his lawn growing up. Will graduated from Cornell with a B.S. in Environmental and Sustainability Sciences, with a concentration in Land, Air and Water Resources.

Final Thoughts on Choosing the Right Milky Spore Product for Your Yard

Applying milky spore is a great organic method of getting rid of your Japanese beetle grub infestation.

While both powders and granules are effective, natural options, I highly recommend using the granular version of the product and applying it in your lawn spreader. The granular form is much more resilient against weather after application and doesn’t have the same risk of runoff during rainfall. It’s also easier to get an even application across your property.

Things to Remember

  • Giving the milky spore bacteria a strong presence in your lawn is essential to provide long-term protection against the Japanese beetle grubs. This is not a single-application product. For lasting results, apply in the spring, summer, and fall for two consecutive years.
  • Before you apply, make sure that you are targeting the grub population you currently have in your lawn. The product I’ve recommended here specifically targets Japanese Beetle grubs, and may no work for you if you live in a place where this type of insect is not present or well established (reference the map below).
Japanese Beetle Population in the US (Map)
Fig 1. Map of continental US showing the status of the Japanese beetle invasion, by county: well established (red), establishing (orange), occurrences reported (yellow), and no occurrences known (white). [source]

If you do not live in an area where Japanese Beetle grubs are present, consider this alternative biological control from Sunday which targets more species of grubs (my readers can save 15% with code LAWNCHICK2024).

At Lawn Chick, I am committed to publishing accurate, useful, and trustworthy resources for my readers. As part of this commitment, I’ve invited subject matter experts to review our articles for accuracy. I invite you to read our editorial policy and publishing standards which outlines in detail how every article on this site is sourced, edited, fact-checked, and vetted.



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.

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