• EM-1 Effective Microorganisms — white 1L bottle with green Dr Higa's Original EM-1 label, Agriton Group branding
  • EM-1 Effective Microorganisms — close-up of bottle label, Effective Micro-Organisms wording
  • EM-1 Effective Microorganisms — close-up of green back label with Applications and dilution instructions
  • EM-1 Effective Microorganisms — close-up of green back label with Introduction, Description and Effects of EM-1
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Dr Forest

EM-1 Effective Microorganisms | Probiotic Feed

EM-1 Effective Microorganisms | Probiotic Feed

£25.00 GBP
£25.00 GBP
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EM-1 Effective Microorganisms — a live soil probiotic you activate and feed

Live Microbial Inoculant Soil Probiotic KNF & JADAM Ready Non-GMO Cultures No Animal By-Products For Plants & Soil
Garden use only

This is a soil and compost biostimulant for plants. It is not a food, drink or human supplement, and is not tested to food-grade or supplement standards. Keep it for the garden.

EM-1 is a living culture of beneficial microbes, kept dormant in a mildly acidic liquid and woken up with molasses and water. The blend brings together three groups that work in concert: lactic acid bacteria, yeasts and phototrophic (photosynthetic) bacteria. Add them to soil, compost or a kitchen caddy and you are topping up the working microbial life that drives decomposition, nutrient cycling and a healthy root zone.

One 1-litre bottle is a concentrate, not a ready-to-use spray. Mix it with Dr Forest Unsulphured Molasses and water, ferment it for a week or so, and a single litre becomes 20 litres or more of activated culture. You control the freshness, you control the cost per litre, and there is nothing in it derived from animals.

BillionsLive microbes / teaspoon
1 : 1 : 20EM · Molasses · Water
20×+Activated from one litre
3Core microbe groups

What gardeners use it for

  • Soil drench — water diluted culture into beds, borders and pots to build soil biology over a season.
  • Compost accelerator — speeds the breakdown of a heap and keeps it sweeter-smelling.
  • Bokashi fermentation — the microbial engine behind kitchen food-waste fermenting (pairs with bokashi bran).
  • Seed & seedling soak — a weak solution before sowing or potting on.
  • Foliar mist — well diluted, over leaves as part of a microbial programme.
  • Animal housing & coops — a dilute spray to manage odour in runs, sheds and bedding.
  • Wormeries & drains — supports breakdown and keeps things from turning foul.

Concentrate you activate vs ready-to-use sprays

Dr Forest EM-1 concentrate

  • One litre activates to 20 litres or more with molasses and water.
  • You brew it fresh, so the microbes are live when they reach the soil.
  • Far lower cost per applied litre than pre-diluted products.
  • Non-GMO cultures, no animal by-products.

Pre-diluted microbial sprays

  • Already watered down, so you pay to ship mostly water.
  • Shorter useful life once the culture has been sitting on a shelf.
  • No control over the activation or freshness.

From Dr Forest — a grower-run brand based in Stockport.

What Effective Microorganisms are, and what the evidence actually shows

A consortium, not a single bug

The Effective Microorganisms approach was developed by Professor Teruo Higa at the University of the Ryukyus, Okinawa, in the 1980s. The idea is simple: rather than one isolated strain, you culture a stable community of compatible microbes that get along in the same acidic, low-oxygen liquid. The three groups in EM-1 are lactic acid bacteria, yeasts and phototrophic (photosynthetic) bacteria.

They sit dormant until molasses gives them a sugar source and water rouses them. Once active, they ferment rather than rot, which is why an EM-treated heap or caddy smells sweet and sour instead of putrid.

Ferment, don't rot — the whole point of EM is to steer organic matter down a fermentation pathway.

The honest evidence picture

The literature on EM is genuinely mixed, and it is worth being straight about that. A review of vegetable trials found a positive effect on growth in roughly 70% of published studies, with no significant effect in the rest (Olle & Williams, 2013). Long-term field work in China recorded higher wheat yields and better nutrition where EM was applied alongside compost over many seasons (Hu & Qi, 2013). Against that, a careful four-year temperate field study found no reliable effect on yield or soil quality, and concluded that much of any benefit tends to come from the organic matter EM is carried in rather than the microbes alone (Mayer et al., 2010).

The practical reading: EM is most dependable as a fermentation and composting aid, and as part of a soil programme built around organic matter — not as a stand-alone yield booster. Treat it as one input in a living-soil approach, not a silver bullet.

How the microbes earn their place

01

Lactic acid bacteria

Ferment sugars into lactic acid, dropping the pH. That acidic, fermentative environment is what keeps spoilage and putrefaction in check in a compost heap or bokashi bin, and is the basis of the same lactic fermentation used in silage and food preservation.

02

Yeasts

Produce enzymes, organic acids and growth substrates as they work through sugars. These by-products feed the other microbes in the culture and contribute to the breakdown of organic matter.

03

Phototrophic bacteria

Use organic compounds and root exudates and release amino acids and other simple compounds. Reviews describe these substrates supporting other beneficial soil organisms, including mycorrhizal associations in the root zone (Olle & Williams, 2013).

04

Fermentation over putrefaction

By steering organic matter down an anaerobic fermentation route, EM reduces the odorous compounds produced when material simply rots. This is why it is widely used in bokashi composting and for odour in animal housing.

05

Best alongside organic matter

Trials consistently show EM performing better with compost, manure or molasses than on its own — controlled work in beans found EM maintained leaf photosynthetic efficiency and lifted seed yield when applied to organically amended substrates (Iriti et al., 2019). Feed the soil and the microbes together.

Scientific References

  1. Higa, T. & Parr, J.F. (1994). Beneficial and Effective Microorganisms for a Sustainable Agriculture and Environment. International Nature Farming Research Center, Atami, Japan.
  2. Olle, M. & Williams, I.H. (2013). Effective microorganisms and their influence on vegetable production – a review. Journal of Horticultural Science & Biotechnology, 88(4), 380–386.
  3. Hu, C. & Qi, Y. (2013). Long-term effective microorganisms application promote growth and increase yields and nutrition of wheat in China. European Journal of Agronomy, 46, 63–67.
  4. Iriti, M., Scarafoni, A., Pierce, S., Castorina, G. & Vitalini, S. (2019). Soil application of effective microorganisms (EM) maintains leaf photosynthetic efficiency, increases seed yield and quality traits of bean (Phaseolus vulgaris L.) plants. International Journal of Molecular Sciences, 20(9), 2327.
  5. Mayer, J., Scheid, S., Widmer, F., Fließbach, A. & Oberholzer, H.-R. (2010). How effective are ‘Effective microorganisms (EM)’? Results from a field study in temperate climate. Applied Soil Ecology, 46(2), 230–239.

How to activate and apply EM-1

Water quality first

Chlorine in mains tap water kills the cultures. Use rainwater, or stand tap water uncovered for 24 hours so the chlorine gasses off, before activating or diluting.

Step 1 — activate it with molasses

EM-1 is a concentrate. To get the most from it, brew a batch of activated culture first. The molasses is the food source that wakes and multiplies the microbes.

You will need molasses

Activation needs Dr Forest Unsulphured Molasses. Use unsulphured only — the sulphur dioxide in sulphured molasses inhibits the microbes. (See your basket cross-sells, or search "Dr Forest Unsulphured Molasses" in our shop.)

  1. Mix. Combine in the ratio 1 part EM-1 : 1 part molasses : 20 parts warm dechlorinated water (for example 50 ml EM-1 + 50 ml molasses + 1 litre water). Stir the molasses until fully dissolved.
  2. Seal. Pour into a clean airtight container, filled near the top to limit air. Keep it warm, ideally 20–35°C.
  3. Burp. For the first few days, briefly release the gas that builds up, then reseal.
  4. Wait. Ferment for 7–10 days. It is ready when it smells sweet and sour and the pH has dropped below about 3.5.
  5. Use. Use your activated culture within about 30 days. Refrigeration extends it. A white film on top is normal; black, blue or foul-smelling growth means the batch has spoiled — start again.

Application rates

The dilutions below follow the product's standard guidance. EM is forgiving — err toward weaker rather than stronger, and apply little and often.

Soil & seedbeds

Dilution: 1% solution  |  Timing: from 2–3 weeks before sowing

Water or spray a 1% solution onto the soil 2–3 weeks ahead of sowing, repeat just before planting out, and continue roughly every two weeks. Suits beds, borders, vegetables, soft fruit and ornamentals.

General garden & foliar

Dilution: around 1%  |  Frequency: every 1–2 weeks in the growing season

Apply as a soil drench or a well-diluted leaf mist as part of a regular microbial routine. Best on a dull day or in the evening, not in strong sun.

Animal housing & coops

Dilution: 2% solution

Spray a 2% solution in runs, sheds, stables and on bedding to help manage odour, and onto slurry or muck heaps.

Allotment & plot scale

Rate: 1–10 litres per hectare

At land scale, apply 1–10 litres of EM per hectare depending on the crop and the condition of the soil, diluted into your watering volume.

Five common mistakes

  • Using chlorinated tap water. It kills the culture before it can do anything. Rainwater or stood water only.
  • Sulphured molasses. The sulphur dioxide inhibits the microbes — unsulphured is essential.
  • Applying neat, or far too strong. EM works diluted and regular, not concentrated and occasional.
  • Mixing it with chemicals. Pesticides, fungicides and strong feeds can wipe out the live cultures (see FAQ).
  • Brewing too cold. Below ~20°C the ferment stalls and risks spoiling. Keep it warm.
Works well combined with…

Dr Forest Unsulphured Molasses for activation; Dr Forest Bokashi Bran for fermenting kitchen food waste; and our Liquid Veg & Bloom Boosters, which are already EM-fermented feeds if you would rather skip the brewing. All available in our shop.

Storage

Keep the concentrate sealed, cool and out of direct sunlight; it stays viable for around a year. Do not freeze. Use activated batches within about 30 days, sooner if kept warm.

EM-1 — your questions answered

No. This is a garden and compost product. It is not food-grade, not produced or tested to supplement standards, and not intended for human or pet consumption. Please use it only on soil, compost and plants.
It is a live culture combining lactic acid bacteria, yeasts and phototrophic bacteria, kept dormant in a mildly acidic liquid. The approach was developed by Professor Teruo Higa in the 1980s. Activated with molasses and water, it is used to support soil biology, speed composting and ferment food waste.
For value, yes — activation turns one litre of concentrate into 20 litres or more. You can use small amounts of the concentrate neat in a hurry, but most gardeners brew an activated batch with molasses and water first. It is cheaper and the microbes reach the soil live and freshly multiplied.
Sulphured molasses contains sulphur dioxide, used as a preservative, which inhibits the very microbes you are trying to grow. Unsulphured molasses is a clean sugar source that lets the culture multiply freely. Dr Forest Unsulphured Molasses is made for exactly this.
No — do not mix them in the same tank or apply together. These are living cultures, and pesticides, fungicides and harsh synthetic products can kill them, leaving the EM ineffective. Keep your apparatus clean and free of chemical residues, and apply EM separately.
Yes. It fits naturally into Korean Natural Farming and JADAM-style growing as a ready-made microbial culture, and sits alongside home-brewed inputs such as a JADAM microbial solution. Many growers use it as a reliable, consistent starting culture.
It varies by use. Composting and odour benefits show within days to a couple of weeks. Soil-biology and plant effects build gradually over a season of regular use, and the evidence is strongest when EM is applied alongside compost and organic matter rather than on its own.
The cultures are beneficial soil and fermentation microbes, not pesticides, so it is gentle in the garden. As with any garden product, store it out of reach of children and pets and keep the area tidy after use. It is not for consumption.
A pleasant sweet-and-sour, slightly yeasty or vinegary smell is exactly right and means the culture is healthy. A foul, rotten or putrid smell, or black or blue growth, means a batch has spoiled — discard it and start a fresh activation.
It comes from Dr Forest, a grower-run brand based in Stockport. The cultures are non-GMO and naturally derived, and it is made with organic ingredients. It is not separately certified organic, and we do not make that claim.
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