Top 5 Mistakes New Mushroom Growers Make (and How to Avoid Them)

So, you've taken the leap into the world of mushroom cultivation—welcome! Growing mushrooms at home is incredibly rewarding, but like any new skill, there’s a learning curve. At Colorado Cultures, we’ve helped thousands of new growers get started, and we’ve seen firsthand where things commonly go off track. Here are the top 5 mistakes new mushroom growers make—and how you can avoid them for a successful (and bountiful) first flush.

1. Not Prioritizing Cleanliness

The Mistake: Skipping sterile technique during inoculation or opening bags in a dusty, open space with moving air.

Why It Matters: Mushrooms are picky when it comes to contamination. Mold and bacteria love the same nutrient-rich environment as your mycelium.

How to Avoid It: Always use clean hands, gloves, a face mask, and sanitize your tools with 70–99% isopropyl alcohol. We recommend working in a still-air box or near a flow hood for the cleanest results.

2. Messing with the Grow Chamber Too Much

The Mistake: Constantly opening your grow chamber or bag to check on progress or to “help” the mushrooms grow.

Why It Matters: Every time you open the fruiting chamber, you risk disrupting the delicate balance of humidity and airflow—and you introduce contaminants that could derail your entire grow.

How to Avoid It: Less is more. Once you’ve initiated fruiting, leave the chamber closed unless it visibly needs more moisture. If the surface is looking dry, lightly mist using a fine spray. Otherwise, trust the process. Mushrooms thrive in a stable, undisturbed environment. Watch your substrate’s surface for clues of it being dry.

3. Not Providing Enough Fresh Air Exchange (FAE)

The Mistake: Leaving grow bags or monotubs sealed too tightly during fruiting.

Why It Matters: Mushrooms breathe oxygen and release carbon dioxide. Without fresh air, they become leggy or don’t fruit at all.

How to Avoid It: Cut appropriate holes in your tub or open your grow tent a few times a day. Our Full Flush Mushroom Grow Kits are designed with built-in ventilation that balances humidity with FAE, making this step much easier.

4. Not Keeping a Consistent Temperature

The Mistake :Letting temperatures fluctuate too much during colonization or fruiting stages.

Why It Matters: Mushrooms need stable conditions to grow efficiently. Too hot, and you risk bacterial contamination. Too cold, and growth slows dramatically—or stalls entirely.

How to Avoid It: Aim for a consistent temperature of 70–80°F during colonization and slightly cooler (70-75°F) during fruiting, depending on the strain. Avoid placing your grow setup near windows, heaters, or AC vents where temperature swings are common. A thermometer near your kit can help you stay on track.

5. Not Choosing the Right Supplies

The Mistake: Starting with low-quality substrate, spores from unverified sources, or improperly prepped kits.

Why It Matters: Even perfect technique can’t make up for poor materials. Substrate is the foundation of a successful grow.

How to Avoid It: Use trusted suppliers (like us!) for high-quality, ready-to-go grow kits and clean cultures. Our Denver Dirt substrate is specifically formulated to optimize performance and reduce failure rates—even in dry Colorado conditions.

Grow Smart from the Start

Making mistakes is part of the learning process, but with the right supplies and a little guidance, your first mushroom grow can be a smooth and satisfying experience. At Colorado Cultures, we’re here to help every step of the way—from selecting your first kit to your first harvest and beyond.

Stop by our stores in Englewood or Wheat Ridge, or shop online for grow kits, tools, and support you can count on.