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 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.
There are many brand names for effective microorganism products, such as EM-1, Efficient Microbes or Biosa, but one of the biggest brands has also become the generic term, effective microorganisms. The 5-20 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.
What Is Effective Microorganisms Good For?
More important than all of this 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 Of EM?
There are many other uses of effective microorganisms, 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. And then you may be interested in my Microbial Inoculants online gardening course where I cover effective microorganisms extensively.