​Mushroom Growing Gone Wrong: Lessons Learned and How to Avoid Common Pitfalls

​Mushroom Growing Gone Wrong: Lessons Learned and How to Avoid Common Pitfalls

Posted by Jmaequiogue on Jul 4th 2024

Growing your very own mushrooms may be a very fulfilling activity and a great way to get fresh, organic fungus. It is not without difficulties, though. Numerous problems that can cause frustration and failure plague many gardeners, regardless of skill level. This article examines typical mistakes made when growing mushrooms and offers advice on how to avoid or get beyond them.

1. Contamination Catastrophes

Issue: Contamination is the bane of mushroom growers everywhere. It can occur at any stage, from spore inoculation to fruiting, and can quickly ruin an entire batch. Common contaminants include mold, bacteria, and yeast, which compete with the mushroom mycelium for nutrients.

Case in Point: An novice cultivator excitedly injected oyster mushroom spores into a batch of grain spawn. Regretfully, they did not adequately disinfect their equipment. The entire batch was wasted when green mold grew over the jars in a matter of days.


  • Sterile Techniques: Always use sterile equipment and maintain a clean environment. This includes sterilizing your growing medium, tools, and workspace thoroughly before starting the cultivation process.
  • Quality Control: Use high-quality spawn and spores from reputable suppliers to minimize the risk of introducing contaminants.
  • Environmental Control: Maintain appropriate humidity, temperature, and air circulation in your growing area to prevent the growth of unwanted organisms.

2. Humidity Hiccups

Issue: A certain amount of dampness is necessary for mushrooms to grow. While too much humidity can encourage the growth of mold and other problems, too little humidity can result in stunted growth, dry mushrooms, and decreased yields.

Case in Point: A grower set up a makeshift fruiting chamber in their basement, misting it periodically to maintain humidity. However, they failed to monitor the humidity levels accurately. The chamber became too dry, causing the mushrooms to shrivel and halt their growth.


  • Humidity Control: Use a hygrometer to monitor humidity levels. Aim for a relative humidity of 80-90% during the fruiting stage.
  • Misting: Regularly mist your growing area with clean water to maintain humidity. Be cautious not to over-mist, as this can lead to excess moisture and promote mold growth.
  • Humidifiers: Consider using a humidifier in larger growing setups to maintain consistent humidity levels.

3. Temperature Troubles

Issue: Temperature fluctuations or extreme temperatures can negatively impact mushroom growth. Each mushroom species has specific temperature requirements for different stages of growth.

Case in Point: In their garage, a grower attempted to grow shiitake mushrooms in the summertime. Often, the temperature rose over 80°F (27°C), which is well above the ideal range for shiitake mushrooms. This led to stunted growth and deformed fruiting bodies.


  • Research: Understand the temperature requirements of the specific mushroom species you are growing. For example, oyster mushrooms thrive in temperatures between 55-65°F (13-18°C) during the fruiting stage.
  • Temperature Control: Use heaters or air conditioners to maintain the appropriate temperature range in your growing area. Thermostats can help automate this process.
  • Insulation: Insulate your growing space to protect against external temperature fluctuations.

4. Air Circulation Issues

Issue: Mushrooms need fresh air to grow properly. Stagnant air can lead to the accumulation of carbon dioxide, which can stunt mushroom growth and cause deformations.

Case in Point: An insufficient ventilation system was employed by the grower as a fruiting chamber, which was a sealed plastic tub. The absence of oxygen led to the mushrooms being longer and thinner—a characteristic called "legginess."


  • Ventilation: Ensure adequate ventilation in your growing area. Use fans to promote air circulation and prevent the buildup of carbon dioxide.
  • Air Exchange: Regularly exchange the air in your growing area to introduce fresh air. This can be done manually or through automated systems.

5. Lighting Lapses

Issue: While mushrooms do not require light for photosynthesis, some species need light cues to trigger fruiting. Inconsistent or inappropriate lighting can delay or inhibit fruiting.

Case in Point: A grower attempted to cultivate enoki mushrooms in complete darkness, believing they would grow better without any light. The mushrooms failed to fruit, remaining in the mycelium stage.


  • Lighting Schedule: Maintain a consistent lighting schedule. For example, most mushrooms benefit from 12 hours of light and 12 hours of darkness during the fruiting stage.
  • Light Quality: Use indirect or diffused light rather than direct sunlight. Fluorescent or LED lights can provide the necessary light without generating excessive heat.

6. Substrate Snafus

Issue: The substrate is the material on which mushrooms grow, and it must provide the right nutrients and environment. Contaminated or poor-quality substrates can hinder mushroom growth.

Case in Point: A grower used unpasteurized straw as a substrate for growing oyster mushrooms. The straw harbored bacteria and mold, which quickly outcompeted the mushroom mycelium.


  • Substrate Preparation: Properly pasteurize or sterilize your substrate to kill any existing contaminants. Follow specific guidelines for different types of substrates.
  • Nutrient Balance: Ensure the substrate contains the necessary nutrients for your mushroom species. For example, straw, sawdust, and compost are commonly used substrates for various mushrooms.
  • Substrate Freshness: Use fresh substrates and avoid reusing old ones, as they may be depleted of nutrients and more prone to contamination.

7. Pest Problems

Issue: Pests, such as flies, mites, and rodents, can damage mushroom crops and introduce contaminants.

Case in Point: A grower noticed small flies buzzing around their fruiting chamber. These flies laid eggs in the substrate, and the emerging larvae damaged the developing mushrooms.


  • Physical Barriers: Use fine mesh screens or netting to keep pests out of your growing area.
  • Sanitation: Maintain a clean growing environment and dispose of any waste promptly to avoid attracting pests.
  • Natural Predators: Introduce natural predators, such as beneficial nematodes, to control pest populations.

8. Overwatering Woes

Issue: Overwatering can lead to excess moisture, creating a breeding ground for mold and bacteria. It can also suffocate the mushroom mycelium, hindering growth.

Case in Point: A grower diligently watered their mushroom substrate multiple times a day, believing that more water would lead to better growth. Instead, the excess moisture caused the substrate to become waterlogged, resulting in mold growth and a failed crop.


  • Watering Schedule: Water your substrate and growing area according to the specific needs of your mushroom species. Avoid overwatering and allow the substrate to dry out slightly between watering.
  • Drainage: Ensure proper drainage in your growing containers to prevent water from pooling.

9. Impatience and Interference

Issue: Mushroom cultivation requires patience. Rushing the process or constantly checking the growing medium can disturb the mycelium and delay fruiting.

Case in Point: A beginner grower frequently opened their fruiting chamber to check on progress, inadvertently introducing contaminants and disturbing the delicate environment. This constant interference resulted in delayed fruiting and contamination.


  • Patience: Understand that mushroom cultivation is a slow process. Follow the recommended timelines for your mushroom species and avoid unnecessary interference.
  • Observation: Monitor your growing area regularly but resist the urge to make frequent changes. Allow the mycelium time to establish and fruit.

10. Misidentification Mayhem

Issue: Misidentifying mushroom species can lead to cultivating the wrong type of mushroom, which can be problematic, especially if it turns out to be a non-edible or toxic variety.

Case in Point: A grower mistook a wild mushroom species for a popular edible variety and attempted to cultivate it. The resulting mushrooms were inedible and potentially harmful.


  • Proper Identification: Educate yourself on the characteristics of the mushroom species you wish to grow. Use reliable sources and consult experts if necessary.
  • Labeling: Clearly label your growing containers and substrates to avoid confusion and ensure you are cultivating the correct species.


Mushroom cultivation can be a rewarding and fruitful endeavor, but it is not without its difficulties. Avoid frequent errors and improve your chances of a successful harvest by applying best practices and learning from the experiences of others. Recall that maintaining a clean, regulated environment, being patient, and paying attention to detail are essential for effective mushroom production. You may successfully traverse the challenges of cultivating mushrooms and savor the fruits (or rather, fungi) of your hard work if you keep these guidelines in mind.