How to Grow Mycelium in Petri Dishes

Growing Mycelium

If you like growing mushrooms, you may want to learn how to grow mycelium in petri dishes. Mycelium refers to the vegetative part of fungi. More specifically, it consists of a mass of branching, thread-like hyphae. Agar petri dishes are commonly used to grow and study mycelium. And now, here are some steps to help you grow mycelium in an agar petri dish:


  • Agar petri dish
  • Fungal spores or mycelium
  • Sterile water or broth
  • Sterile syringe or pipette
  • Incubator or warm location (around 25-30°C)


  1. Prepare the agar according to the instructions on the nutrient mix package, as described in the previous answer.
  2. Inoculate the agar with either fungal spores, liquid culture or mycelium. If using spores, use a sterile syringe or pipette. Place a drop of sterile water or broth containing the spores onto the center of the agar. When using mycelium, transfer a small piece of the mycelium onto the agar using sterile forceps.
  3. Seal the petri dish with tape or parafilm to prevent contamination.
  4. Incubate the petri dish at around 25-30°C in an incubator or warm location. Sometimes, different fungi may have different optimal temperatures.  Consult literature or research publications for specific temperature recommendations.
  5. Observe the growth of the mycelium over the next few days or weeks. As the mycelium grows, it should form a visible network of branching hyphae.
  6. In order to study the mycelium further, you can transfer a small piece of the mycelium onto a new petri dish with fresh agar. This process is called subculturing. Repeat multiple times to create a pure culture of the fungus.
How to Grow Mycelium blog

How to identify healthy mycelium in petri dish

When growing mycelium in a petri dish, it is important to identify healthy mycelium and differentiate it from other types of growth or contamination. Here are some characteristics of healthy mycelium to look for:

  1. Appearance: Healthy mycelium should appear as a network of branching, thread-like hyphae that form a visible layer on the surface of the agar. As such, the color of the mycelium will depend on the type of fungus being grown. It should be uniform and not have any discoloration or dark spots.
  2. Growth rate: Healthy mycelium should be growing at a steady rate. If the mycelium growth is slow, uneven or non-uniform, this could indicate an issue with the growth conditions, such as temperature or nutrient availability.
  3. Texture: Healthy mycelium should have a smooth texture on the surface of the agar. If the surface appears rough, uneven or bumpy, this could indicate contamination or a growth problem.
  4. Odor: Healthy mycelium does not typically produce any odor. However, if the mycelium has a foul or unusual odor, this is a sign of contamination or other issues.
  5. Lack of contamination: Healthy mycelium should not have any other types of growth or contamination in the petri dish. If there are spots or growth that are different from the mycelium, this could indicate contamination or issues with the growth conditions.

It is important to maintain a sterile working environment and use proper techniques to prevent contamination in your cultures. For example, always wear gloves and a lab coat, and sterilize any equipment and surfaces that will come into contact with your cultures.