How to Collect Indigenous Microorganisms (IMO) for Your Garden – The Organic Gardener’s Guide

Imagine giving your soil a rich diet of local microorganisms that nurture its health, retain moisture, and reduce the need for costly fertilizers. That’s the magic of Indigenous Microorganisms, or IMO, and they’re not only free and natural but also profoundly effective at improving garden soil.

In this guide, you’ll learn everything you need to know about building your collection box, collecting IMO, and preserving your collection to ensure you’ve got a year-round supply of microbial goodness. Let’s break down each step, making it easy, approachable, and dare I say, quite a bit of fun.

Why Collect IMO?

Indigenous Microorganisms are microorganisms found naturally in healthy ecosystems, such as forests. By introducing them into your garden, you’re boosting the soil’s ecosystem with organisms well-suited to your local environment. Unlike store-bought soil amendments, IMO are precisely adapted to local pests, pathogens, and climate conditions.

IMO benefits include:

• Improved Soil Health: IMOs enhance nutrient cycling, supporting plants and helping you save on fertilizers.
• Water Retention: Healthy, microbe-rich soil can retain moisture better.
• Natural Pest Resistance: Because they’re local, IMOs create a balanced ecosystem that wards off invasive species and diseases.

Getting Started: Putting Together an IMO Collection Box

The first step in IMO collecting is prepping your collection box. Think of this as a cozy Airbnb for microorganisms, giving them an ideal environment to grow.

If you need info on how to first build your collection box, pop on over to our article about Building Your IMO Collection Box with Cedar Wood here.

Materials You’ll Need:

• Cedar wood box (roughly 12”x12”x4” is perfect)
• Rice (white rice, as it’s more attractive to microbes)
• Paper towel or breathable cloth
• Rubber band or twine
• Optional: small mesh wire to protect the collection box. (I use chicken wire cut to fit and bent around the top to keep small animals out.)

How To Prepare Your Collection Box:

1. Prepare the Rice: Cook about 4 cups of rice. Aim for al dente (cooked but still slightly harder than you’d like to eat it). Measurements can vary depending on your local humidity, but roughly 3/4 cup or water per 1 cup of rice works best for me. You may have to play around with it once or twice to get the perfect blend for your area – don’t be discouraged if it takes a couple tries!
2. Pack the Box: Spread the rice evenly in the wooden box. Don’t pack it down hard – leave some breathing room for the micro-organisms to spread out!
3. Cover the Box: Place a breathable cloth or paper towel over the top of the box and secure it with a rubber band. Wait until you get to your collection area to add the mesh wire shield – more on that later.
4. Have a Shield Ready: You might want to attach a small wire mesh over the cloth as an extra layer. This is the easiest way to protect your collection from curious forest creatures munching your rice and ruining your collection – once they touch it, it’s no longer safe to use and should be tossed out. Save yourself the frustration and go for the mesh.

Finding the Perfect Collection Spot

When choosing a spot for IMO collection, the goal is to find a location rich with microbial life. Ideal locations include forest floors, undisturbed garden beds, or beneath the shade of a healthy tree. Look for areas with organic matter—like leaf litter or rotting logs—and stay close to home, as microbes adapted to your local environment are best for your garden.

Placement Tips:

• Look for an area with visible mycelium. (Figure 1 above shows the healthy mycelium you want to be on the lookout for. They will look like thin, white hairs growing just beneath or on top of the soil and rotting logs.)
• Place the box in contact with the soil but not buried in it.
• Lift a corner of your box’s covering and place a small piece of mycelium inside. Be sure that the mycelium strand is clear of dirt and debris. Then close the covering and bend your wire mesh over top of the covered box for added protection.
• Cover the box lightly with fallen leaves, and bits of mycelium or brush to replicate a natural forest floor. Be sure to not pile it heavily on as this may poke holes in your covering.
• Choose a spot that stays relatively moist but isn’t flooded, as overly wet conditions can hinder microbial growth.
• Be 100% sure that it isn’t going to rain on your box. If rain is forecasted you can create a little tent for your box with a tarp. Hang the tarp over the box at an angle to ensure that plenty of airflow will get to all sides and the top of your box but rain will not.

The Waiting Game

After setting up your collection box, you’ll want to leave it undisturbed for around 5-7 days. During this time, beneficial microorganisms from the surrounding soil and decomposing matter will begin to colonize the rice.

What You’re Looking For:

• The rice should develop a white, fluffy coating—this is the mycelium, or beneficial fungal network, working its magic.
• Avoid rice that looks black or slimy, which indicates that the spot was too damp and has likely encouraged less desirable bacteria.

Harvesting Your IMO

Once you’ve got a healthy-looking collection of white mycelium (or “fluff”), it’s time to harvest. Carefully remove the rice and mycelium mixture, taking care not to disturb the delicate microorganisms. You don’t have to wear gloves to do this but it’s recommended. The rice can become a bit hard in places and it’s possible to accidentally cut yourself on it when mixing it (I speak from experience). So, unless you’d like to mix a little of ‘you’ into your IMO fermentation, go for some thicker chemical gloves like these.

Preparing Your IMO for Storage or Immediate Use

There are two main ways to preserve your IMO: using brown sugar or drying it for later. Both methods help stabilize the microbes, so you can use them when ready.

Method 1: Brown Sugar Preservation

1. Combine with Brown Sugar: Weigh your rice-mycorrhizae mixture and mix it with an equal weight of brown sugar. This will halt microbial growth, keeping the IMO in a dormant state.
2. Store in a Cool, Dark Place: Transfer the mixture into a glass jar with a loose-fitting lid or paper towel and rubber band. Store it somewhere cool and out of direct sunlight. Properly stored, this preserved IMO can last several months.

Method 2: Drying for Long-Term Storage

1. Spread Thinly on a Tray: Spread the rice mixture thinly over a mesh tray or drying rack.
2. Air Dry in the Shade: Allow the rice to dry in a well-ventilated area, ideally in the shade. Once dry, you can crumble it into a fine powder for easier application.

Tip: If you’re not collecting IMOs regularly, try to gather a fresh batch in the fall, when microbial diversity peaks. Fall-collected IMO is especially resilient and robust, perfect for introducing into your garden’s winter soil prep routine.

Using Your IMO in the Garden

Once you’ve collected and stored your IMO, it’s time to use it! Here are a few ways to incorporate this organic gold into your gardening routine:

1. Soil Amendment: Mix IMO into your garden soil as part of your winter prep. Simply scatter it across your beds and cover with mulch or fallen leaves. This lets the microorganisms populate the soil before planting season.
2. Compost Booster: Add a scoop of IMO to your compost pile to encourage faster decomposition and create a nutrient-rich compost full of beneficial microbes.
3. Liquid Application: Mix a tablespoon of your dried IMO powder with water and spray it on plants or soil. This method is excellent for a quick microbial boost, especially during the growing season.

Tips for Successful IMO Collection and Application

• Rotate Collection Spots: Every few months, choose new locations to encourage biodiversity.
• Be Patient: IMO collection is a natural process, so let it take its course without rushing it.
• Check for Pests: Before bringing your IMO indoors, inspect it for hitchhiking bugs to keep your storage area pest-free.

Why IMO Collection Is a Must for Organic Gardeners

Incorporating IMO into your gardening routine is a rewarding way to build soil health, encourage biodiversity, and create a thriving, balanced ecosystem. It’s a natural, cost-effective method that aligns with organic practices, and it’s a fun way to connect with your environment on a deeper level. While collecting IMO requires a little patience and setup, the benefits far outweigh the effort—resulting in a more resilient, productive garden without the need for synthetic fertilizers or chemicals.

So this season, consider giving IMO collection a try. Your soil—and future harvests—will thank you for it!

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Happy collecting, and may your soil be as lively as the forest floor itself!