Effective Microorganisms® (EM®) – Best Inoculant For You

Effective Microorganisms (EM)

I’ve been referring to Effective Microorganisms® (EM®) a fair amount on this blog, so I figure it’s time to get into more detail as to why it’s so incredible to use in organic gardening.

What is EM?

“Effective microorganisms” is a liquid culture of specific “facultative anaerobic” microbes that can provide amazing benefits for your organic garden when combined together in specific proportions.

Facultative anaerobic means microbes that can live both in air with oxygen, and also in low oxygen conditions. They’re also called fermenting microbes and some of them are responsible for making your bread, beer, wine and yogurt.

Many of the 30 locally-sourced microbes in the inoculant are found all over the world, but when we put them together, the magic begins.

The mother culture is not something you can make at home, but you can buy it from a manufacturer with the equipment and knowledge to put them together in exactly the right proportions and under the right environmental conditions.

The 3 microorganism groups are lactic acid bacteria, yeast and photosynthetic bacteria, plus many other wild microbes that will be let into the brew.

Many people, including myself, tend to use “effective microorganisms” and “EM” as generic terms to describe many different brands of similar products that exist, but in reality, EM and Effective Microorganisms are either registered trademarks or trademarks of EM Research Organization, Inc. in the United States and/or other countries.

I’ve used the authentic EM products marketed by TeraGanix and I’ve also used SCD’s products. I’ve been happy with all of these products. I haven’t tried others. I’m sure there are a few good ones and probably plenty of bad knock-offs.

What Is Effective Microorganisms And Similar Products Good For?

More important than which individual species of microorganisms are in these products is how they work together and provide for each other to contribute a host of benefits to our organic garden.

They create an abundance of antioxidants, controlled breakdown of organic matter, and according to some people, an extremely positive energy force.

Really, I think of them as providing all of the same benefits as the other beneficial microbes I hope to house in my vegetable garden and ornamental gardens, but they just happen to be exceptionally good at it when they get together.

Take any of them out or even change the proportions in the mix too much and you no longer have EM or the same benefits.

Effective microorganisms was originally developed and used in agriculture where it was found to improve compost and soil organic matter breakdown. It was even found to have a beneficial effect on other microbes in the soil, coaxing them to get to work.

It isn’t as well known in the United States or Canada yet, but it’s used in over 150 other countries and there have been thousands of trials showing its effectiveness.

After its value was seen in soil and composting, EM started to be used in other areas with astounding results. It has helped plants beat diseases such as Botrytis, insects such as weevils and other stressors.

It’s not a pesticide and can’t be marketed as such. It simply creates health in the plant and helps to outcompete predators. It also helps crops achieve higher brix and longer storage. One study sticks in my mind because a 50% increase in yield was obtained just with EM.

What Are Some Other Uses?

There are many other uses of effective microorganisms and similar products, such as:

  • to control odors, diseases and insects on animals
  • to clean polluted water, septic systems and sewers
  • to make bokashi, which can be used to pickle your food scraps
  • an amazing probiotic for humans
  • in deodorant, toothpaste, cleaning, laundry, odor control
  • for garbage dumps, soil remediation, cleaning hospitals, oil spills

Now of course, like any mixture of beneficial microbes, EM is not a magic bullet and results vary depending on many environmental factors, but I have found it can work some miracles, sometimes very quickly and sometimes only when used consistently over a number of months.

Any questions? Let me know below.

Update: 2 1/2 years after writing this, I started selling the product I use from SCD Probiotics, which you can check out here.

Effective Microorganisms, EM, and EM1 are registered trademarks of EM Research Organization in Japan. TeraGanix is the exclusive distributor for EM Technology in the US and Canada.


  1. Renate on April 5, 2011 at 12:35 am

    We have started a garden of overly ambitious size (50 x 115 feet- a lot for one person to manage!), hoping to produce a variety and sizeable quantity of produce. However, it’s size has me somwhat intimidated and I am seldom able to concentrate on all the techniques you spell out in your lessons. Since it used to be a field behind our rural home in central Texas, I am battling with this network of ‘evil’ grasses with runner roots that are almost impenetrable. We’re only in our second year, but I hope that each year, as I spend countless hours sifting and digging them out, I might inch my way to an improvement. So my goals, not necessarily in the order of importance, are 1.) To get it to where there are mostly just the ‘regular’ weeds throughout the garden. 2.) To create a unique decorative entrance/gate, pretty corners, edges, and vignettes here and there to give me visual pleasure as I work. I’ve established meandering paths through the space, inspired by the Japanese garden aesthetic where there are no straight lines in nature. 3.) To grow mostly heirloom vegetables, and save seeds from year to year. 4.) And I am concerned with getting the organic content of the beds built up. So… I’m a bit overwhelmed. Hopefully, I can concentrate on improving just a couple of the beds at a time, add some compost now, and maybe do some (lasagna) layering in between seasons. Any advice for such a project?

    • Phil on April 5, 2011 at 2:43 pm

      Hi Renate, wow that is ambitious. It sounds like I’m too late, but my firstadvice for others reading this would be to start smaller and work your waybigger, rather than being in a constant state of overwhelm. What I would doif I were you is take a big part of the garden and cover crop it. Covercrops are an amazing way to build your soil when you don’t have enoughcompost/mulch materials. In most of North America, a mixture of clover orvetch and cereal rye or annual ryegrass works well, but central Texas may bea bit different. A good garden centre will know. A grass is better than alegume for building long-term organic matter, and you can find one thatwon’t be weedy.

      • jonathan lawrence on April 7, 2011 at 2:56 am

        i love how masanobu fukuoka started to improve soil with dandelions, burdock, & daikon. dandelion especially because it is one of my favorite plants of all time. i have a hundred thousand dandelion seeds or so, but i don’t know how long they stay viable or if they need to be stratified..

        • Phil on April 7, 2011 at 1:46 pm

          Yes, dandelions are wonderful for the soil and for us. Daikon, too.

  2. JonathanBrown20 on October 29, 2011 at 12:22 pm

    Does EM compete with other compost tea microbes, or does it promote their well being? If the latter, how does it work?

    • connie milne on October 29, 2011 at 8:44 pm

      It enhanses your compost tea.  I add EM to the compost tea right before I spray it on my garden.  All good things rolled into one.  Compost Tea is aerobic and eM IS anaerobic and each one benefits diferent organisms.

    • Phil on October 30, 2011 at 5:02 am

      Hi Jonathan, EM microbes get along well with compost tea microbes. When I first started, I was taught differently, so I was always alternating between compost tea and EM applications, which was a pain. Then I did more research and learned that EM is a really nice ingredient in compost tea. And even if not used as an ingredient, it’s great to combine them during application.The microbes in EM promote the well being of many other microbes just by virtue of the things they do. It’s probably fairly complicated how it all works. They produce hormones, enzymes, vitamins, amino acids, sugars, and other bioactive substances. They do all kinds of good stuff. These processes help some microbes out and keeps other microbes in check. It’s all very complex, and definitely interesting.

  3. Day on October 29, 2011 at 8:50 pm

    I hope you made a video for EM too!

  4. Sallyslak on October 30, 2011 at 7:09 am

    Hi Phil – I’ve been enjoying your video series, thanks!  Have you had any luck brewing your own EM?  It’s quite expensive to buy and I had no luck with my first attempt. I haven’t used it much on plants as yet, but is’s great at keeping down the ammonia smells in the chicken and sheep sleeping quarters.Sally

    • Phil on October 30, 2011 at 12:22 pm

      Hi Sally, yes I’ve activated hundreds of gallons of EM over the last few years. I go into great detail on how to do it in the Smiling Gardener Academy, but that won’t be available until 2012, so perhaps I’ll write a blog on just the basics in the next couple of months.

      • Sallyslak on October 31, 2011 at 2:22 pm

        Excellent! I understand your reasoning for delaying the Academy but the timing’s lousy for us southern-hemispherers  :-)Sally

        • Phil on November 3, 2011 at 12:12 am

          Ya, I’m sorry! It was a difficult decision to delay the launch of the academy because I put hundreds and hundreds of hours into it this year, so to have it “sitting on the shelf” for the next few months will be difficult. But it just felt right to wait. Hope you’ll stay tuned to the blog until launch day…

  5. Lynn W on November 2, 2011 at 4:46 am

    I had not heard of this before.  Thanks for explaining it.

  6. Vince Cirasole on January 23, 2012 at 6:47 pm

    I started using endorhizomicrobials this past October on my garlic planting.                They are supposed to give significantly effective support to a plant’s root system.  I won’t be able to report on the results until the plants emerge in the spring.Do your Effective Microorganisms include any rhizomicrobials?  Which ones?

    • Phil on January 26, 2012 at 3:15 pm

      Hi Vince, I think you’re talking about endomycorrhizal fungi, a great product. EM is a great product, too, but it doesn’t contain them. It contains mostly fermenting bacteria.

  7. Glen on March 22, 2012 at 3:48 pm

    Phil I know this is a very busy week for you and congrats on the Academy!  You must be a busy guy right now…I am a week into activating my EM and keep wondering about a couple things.  I understand the molasses feeding the mother culture when activating, but what is the purpose of the other bits of fish, kelp, seacrop…how important are the particular things like this?  Are other inputs possible or even desirable, or are the three normally used for a special reason?Also, I’m anxious to give my indoor plants a kick, and wondered if it’s wrong to use the EM after only a week or two…I remember something about it having to reach a certain pH to make sure it’s “done”.  Does that mean it won’t work or will even be detrimental at this early stage?

    • Phil on March 22, 2012 at 9:53 pm

      Hi Glen, thanks! Yes, it’s a busy, exciting week. It’s important to wait before applying the EM, so if you’re anxious to hit your indoor plants now, I suggest using just a tiny bit of your mother culture. You could just take 1ml and mix it with 2 cups of water and spray your plants. That’s all you need.The other biostimluants are just to give broad spectrum nutrients to the microbes. In my opinion, it’s very helpful to do this, but it’s certainly not necessary. Those 3 are just some of the best biostimulants. There are others, but I stick to those.

  8. CHRIS ARSCOTT on April 23, 2012 at 10:50 am


    • Phil on April 24, 2012 at 5:07 pm

      I would just start searching around online Chris. There are several vendors online and lots of websites.

  9. Colleenjw on May 19, 2012 at 4:08 pm

    Hi Phil – we have a dugout that has poor quality water -is there a ratio to use to improve it

    • Phil on May 22, 2012 at 12:48 pm

      Hi Colleen, it is used in ponds at anywhere from 1 part EM to 200-20,000 parts water in the pond.

  10. Africanaussie on July 30, 2012 at 10:26 pm

    I always thought that air had to be added to everything, and that anaerobic microorganisms were bad.  It seems that everything has their place… I am putting a link to this article in my blog post this week.

    • Phil on August 4, 2012 at 6:10 pm

      Thanks so much!

  11. David on October 17, 2013 at 2:16 pm

    I’m interested in using EM as a probiotic. Does anyone use it this way and know how much to take? I’m also curious about using this stuff to make lacto-fermented vegetables.

    • Phil on October 20, 2013 at 12:52 pm

      I drink probably 1-3 teaspoons of EM every day. I take the regular stuff, but there are food grade ones made for people. For fermenting vegetables, I just make a brine out of salt and water – have not tried adding EM before.

      • melanie on March 14, 2014 at 3:08 am

        So if your EM product can be drunk like a fermented food product, then can the liquid from the fermented foods that I make at home (sauerkraut, pickles, etc.) be used to water my garden or at least in my compost pile?

        • Phil on March 14, 2014 at 1:22 pm

          Absolutely. It won’t bring all the benefits of EM, but there may be some. Those ferments sometimes have a lot of sodium, so you’ll want to dilute them with water.

  12. Nantha on December 13, 2013 at 2:29 am

    Hi Phil- I have been using EM for bio remediation.I want to know whether the EM can survive in aerobic condition or not..

    • Phil on December 16, 2013 at 1:14 am

      Many of the microorganisms survive when put into an aerobic environment (e.g. sprayed into a garden), but the EM culture itself would more quickly move to a different, non-EM mix of microbes if it were to sit, for example, out in a tub with a lot of exposure to the air.

  13. Tori on March 26, 2014 at 10:02 pm

    Just wondering if EM is sold in Atlantic Canada. Can’t find it anywhere other than the west coast.Love your videos; thanks so much for them!

    • Phil on March 27, 2014 at 2:30 am

      Not that I know of. I think it’s only out west right now. But shipping isn’t too expensive from the Organic Gardener’s Pantry.

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