The Home Mushroom Grower’s Guide to Successful Colonization

Colonization Chamber

Share This Post

Colonization chamber for mushroom growing

Mushroom cultivation is becoming an increasingly popular hobby for gardeners and food enthusiasts alike. The process of growing mushrooms at home can be both fun and rewarding, providing you with delicious, fresh fungi to enjoy in your favorite dishes. One of the most critical phases of mushroom cultivation is the colonization phase. In this blog post, we’ll explore what the colonization phase is, why it’s important, and how to successfully navigate it when growing mushrooms at home.

What is the Colonization Phase?

The colonization phase is the stage in mushroom cultivation when the mycelium, the vegetative part of a fungus, spreads throughout the substrate (the material on which the mushrooms grow). This process is essential for the development of healthy, fruiting mushrooms. During colonization, the mycelium absorbs nutrients from the substrate, establishes a strong network, and prepares for the fruiting stage when mushrooms begin to emerge.

Why is the Colonization Phase Important?

The colonization phase is crucial for a few reasons:

  1. Strong mycelium network: A well-colonized substrate provides the foundation for a healthy and robust mycelium network. This network is vital for producing a high yield of mushrooms.
  2. Defense against contaminants: A well-established mycelium is more resistant to contamination from mold, bacteria, and other unwanted organisms, ensuring a safe and successful mushroom crop.
  3. Efficient nutrient absorption: Proper colonization ensures efficient nutrient absorption, providing the mushrooms with the necessary nutrients to thrive.

Steps for Successful Colonization at Home

  1. Choose the right substrate: The first step in the colonization process is selecting an appropriate substrate for your mushroom species. Common substrates include straw, sawdust, and grain. Research the preferred substrate for your chosen mushroom variety and prepare it according to specific guidelines.
  2. Inoculate the substrate: Inoculation involves introducing mushroom spores or mycelium to the substrate. You can purchase spore syringes, liquid culture, or pre-colonized grain spawn from reputable suppliers. To inoculate, inject the spores or liquid culture into the substrate or mix the grain spawn thoroughly. Learn how to make your own grain spawn jars.
  3. Maintain optimal conditions: During colonization, it’s crucial to provide the right environmental conditions. This includes maintaining a consistent temperature (usually between 70-80°F/21-27°C) and high humidity (around 90-95%). You can achieve this by placing the substrate in a closed container, such as a plastic bag or jar, and monitoring the conditions using a thermometer and hygrometer.
  4. Keep it dark: Colonizing mycelium prefers darkness. Keep the substrate container in a dark space, such as a cupboard or closet, to encourage colonization.
  5. Monitor and wait: The colonization process can take anywhere from a few days to several weeks, depending on the mushroom species and environmental conditions. Regularly check the substrate for signs of mycelium growth and contamination. Healthy mycelium will appear as a white, fluffy, or cottony substance.
  6. Shake it up (if necessary): For some substrates, such as grain, it may be necessary to shake the container once or twice during colonization to redistribute the mycelium and promote even growth. Be cautious when doing this to avoid introducing contaminants.

Home-made Colonization Chamber

Colonization Chamber for colonization phase
Lion’s Mane spawn colonizing the chamber. Lid was closed shortly after to conserve heat.

A colonization chamber can easily be made at home with just a few essentials. One of these being the chamber/tub itself. These tubs can be found at almost any home store and are usually used for storage. A 64-80 quart Sterilite tub should work perfectly.

Temperature plays an important role in the colonization phase. During colonization the mycelium enjoys the darkness and warm temperatures to thrive. A heating pad can be used to provide a stable temperature for the tub. This heating pad has proven to be reliable in keeping the temperatures just right.

The last essential you most likely have in your kitchen already believe it or not. It is a cooling rack! A cooling rack should be used to elevate the spawn so that it is not in direct contact with the heating pad. The mycelium relies on ambient temperatures to evenly distribute through the substrate. Direct heat from the mat would cause uneven temperatures within the spawn and give undesired results. These cooling racks should work well with the size heating pad that was listed earlier.


  • Keep your lid closed! The heating pad will be working overtime if you do not trap some heat inside the tub.
  • Elevate your tub or put it on a shelf to keep dust away. Foot traffic around the tub while on the floor is an easy way to introduce dust and contaminates to your tub.


The colonization phase is a critical step in successful mushroom cultivation. By carefully selecting the appropriate substrate, inoculating it with spores or mycelium, and maintaining optimal environmental conditions, you’ll be well on your way to a bountiful mushroom harvest. Remember to be patient and attentive during this phase, as it will set the stage for your mushrooms’ growth and development. With practice and attention to detail, you’ll be enjoying homegrown mushrooms in no time.

Subscribe To Our Newsletter

Get updates and learn from the best

More To Explore

Do You Want To Learn More?

drop us a line and keep in touch