Best humidity for Mycelium Growth (Measuring & Adjust It )

Mycelium, the vegetative part of a fungus, can be found in a variety of different environments. The ideal environment for mycelium growth is one that is moist and has a moderate level of humidity. In this article, we will explore the best humidity for mycelium growth with benefits and discuss some methods for increasing humidity levels in your grow space.

best humidity for mycelium growth

Does mycelium need humidity?

In order for mycelium to grow, it needs humidity. The humidity provides the moisture that the mycelium needs in order to spread. If the humidity is too low, then the mycelium will not grow as well. You can increase the humidity around the mycelium by spraying water on it or by using a humidifier.

Best humidity for mycelium growth

The ideal humidity for mycelium growth is between 85% and 95%. If the humidity is too low, the mycelium will not grow properly and may die. If the humidity is too high, the mycelium will grow too quickly and may not form properly. It is important to monitor the humidity closely when growing mushrooms, as even a small change can affect the results. Here is you want answer How fast do Mushrooms grow after rain?

Relative humidity and mycelium growth

The most important environmental factor for mycelium growth is relative humidity (RH). RH is the percentage of water vapor in the air compared to the maximum amount of water vapor that air could hold at a given temperature. Mycelium grows best when RH is high, between 85% and 95%. If RH falls below 85%, mycelium growth slows and can stop completely at lower levels. If RH rises above 95%, mycelium can grow too quickly and become weak.

Mycelium needs water to grow, but too much water can damage it. When RH is high, mycelium can get all the water it needs from the air.

Effects of humidity on mycelium

The humidity of the surrounding air affects the growth of mycelium. In a dry environment, mycelium grows more slowly and is less likely to produce fruitbodies. Conversely, high humidity can lead to an increase in the rate of mycelium growth and fruiting. Mycelium grown in a high humidity environment typically has a higher moisture content, which can make it more susceptible to mold growth.

In a perfect world, the humidity in your grow room would be just right, allowing your mycelium to colonize your substrate quickly and evenly. However, reality is often not so perfect.

Too much humidity can cause problems such as excessive growth of mold or bacteria, while too little humidity can lead to slow or uneven growth of mycelium. (How to Grow mycelium)

If you are using a humidifier, be sure to clean it regularly to prevent the growth of mold and bacteria.

Optimal humidity for mycelium growth

PeriodHumidity, % PV
Substrate laying53-65
Planting mycelium60
Growing fruiting bodies50-55

In order for the mycelium to germinate, a relative air humidity (RH) of 90% is required, for the formation of a fruiting body 85%. RHV values ​​exceeding 90% lead to the appearance of water droplets on fungi, the development of bacterial diseases and mycoses.

Precautions for maintaining humidity

There are a few precautions that should be taken into account when trying to maintain humidity levels in a space.

  • it’s important to know what the ideal humidity range is for the specific space.
  • it’s necessary to identify the sources of moisture in the area and take steps to address them.
  • proper ventilation is key in order to allow the humidity to circulate properly and prevent mold growth.
  • using a humidifier or dehumidifier can help to regulate the humidity levels in a space as needed.

Adjusting humidity for mycelium growth

There are several ways to adjust the humidity in a growing area. One way is to use a humidifier or dehumidifier to maintain the desired level of humidity. Another way is to use a fan to circulate air and help regulate humidity. Finally, you can adjust the amount of water in your growing medium to regulate humidity.

Benefits of high humidity for mycelium

Humidity is a measure of the amount of water vapor in the air. Mycelium need a high humidity environment to grow and produce mushrooms. In nature, mycelium grow near bodies of water where the humidity is high. In a controlled environment, you can create a high humidity environment by using a humidifier.

Mycelium grown in a high humidity environment will be stronger and more resilient. They will also be able to resist pests and diseases better. The mushrooms that they produce will also be bigger and more plentiful.

Factors that affect humidity levels

There are many factors that can affect humidity levels. Temperature, wind speed, and air pressure are three of the most important factors. When temperature increases, the amount of water vapor that the air can hold also increases. This is why humidity levels are usually higher in the summer than in the winter. Wind speed affects humidity levels because it causes evaporation. The faster the wind blows, the more quickly water vapor is removed from the air. Air pressure affects humidity levels because it affects how much moisture the air can hold. High air pressure means that there is less moisture in the air, while low air pressure means that there is more moisture in the air.

Does mycelium need moisture to grow?

yes, mycelium needs moisture to grow. Mycelium is the vegetative part of a fungus and it requires moisture in order to thrive. If the environment is too dry, the mycelium will not be able to grow and spread. This can lead to problems for the fungus as a whole, since the mycelium is responsible for absorbing nutrients from its surroundings and distributing them to the rest of the fungus.

How do you encourage mycelium growth?

One key to success is encouraging mycelium growth. This can be done by controlling the humidity in the growing environment. By keeping the humidity high, you create an environment that is conducive to mycelium growth. You can do this by using a humidifier or misting the grow area regularly.


In conclusion, the best humidity for mycelium growth is between 95-100%. This range will provide the necessary water to the mycelium while still allowing for good airflow. Keep in mind that the humidity levels in your grow area may vary, so you may need to adjust the humidity levels accordingly.