Learning how to grow mushrooms is like any skill. Sometimes you succeed. Sometimes you fail. The important thing is to keep trying and learn from your mistakes.
Yet it can be really frustrating to start out with what you believe is a successful mushroom project, only to have it produce nothing. Trust me, I know. It’s happened to me many times!
Although many factors may influence your success, there are some common mistakes that can be easily avoided. I’ve listed eight big ones below, along with practical solutions.
If you’re just learning to grow mushrooms, review this list to save yourself both time and heartache. Even if you’re a veteran, it never hurts to come back to the basics.
For more information on how to grow mushrooms and troubleshooting I’d highly recommend Paul Stamets’ books:
As a mushroom cultivator, few things are more frustrating than eagerly checking your grow setup after weeks of patience, only to find little to no mycelium growth. While slow colonization is perfectly normal, seeing zero progress at the two week mark is a red flag that something in your process needs adjustment. Don’t lose hope though – with some troubleshooting and tweaking of your grow conditions, you can get your mycelium back on track.
Why Hasn’t My Mycelium Grown After 2 Weeks? Common Causes
When mycelium growth stalls out after two weeks, the most likely culprits are
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Incorrect temperature. Mycelium thrives between 70-75°F. Temperatures lower than 65°F or above 80°F will drastically slow or stop growth.
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Insufficient humidity. Proper surface conditions are critical. Mycelium requires 95-100% humidity to thrive. Lower levels lead to stalled growth.
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Lack of gas exchange. Without fresh air, CO2 builds up and oxygen runs low. Both conditions hinder mycelium.
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Contamination. Competitor molds and bacteria can overwhelm unestablished mycelium. Their presence stops growth.
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Poor nutrition. Mycelium needs a nutrient-rich substrate with ample carbs nitrogen minerals and vitamins to grow.
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Old or weak spawn. Using aged mushroom grain spawn or spores of dubious viability reduces colonization vigor.
While these factors are the most common culprits, inadequate light, excess moisture, pH imbalance, and genetic weakness can also play a role. Proper troubleshooting is key to get your grow back on track.
Step-By-Step Troubleshooting Guide
Follow this systematic troubleshooting approach if you’re still not seeing mycelium growth after 2 weeks:
1. Check Conditions
Confirm your temperature, humidity and airflow are within the ideal range for mycelium growth. Make any needed adjustments.
- Temperature should be 70-75°F
- Humidity should be 95-100%
- Gas exchange should occur multiple times daily
2. Assess for Contamination
Scan for signs of competitor molds or bacteria: discoloration, foul smells, texture changes. Isolate and discard any contaminated substrate.
3. Evaluate Substrate Nutrition
Ensure your substrate has ample nutrition by using nutrient-rich materials like manure, bran, coffee grounds, gypsum. Supplement if needed.
4. Confirm Spawn Health
Verify your spores or grain spawn are fresh, stored properly, and genetically robust by testing germination rates. Acquire new spawn if viability seems low.
5. Be Patient
Allow more time. Slower genetics or less-ideal conditions could simply need 3-4 weeks rather than 2 weeks to establish. Resist opening containers.
6. Start Over
If all else fails, discard substrate and start fresh with new spawn and sterilized container. Maintain pristine conditions.
While waiting for growth, resist excess handling or drying out your substrate. Keep your patience, maintain ideal conditions, and monitor for subtle signs of progress. With some adjustments, your mycelium growth should regain momentum.
Helpful Troubleshooting Tips
Here are some additional troubleshooting tips for encouraging stalled mycelium growth:
- Misting the surface with pH-balanced water can stimulate growth.
- Elevating temperatures slightly, within the ideal range, can speed colonization.
- Agitating broth culture syringes can rouse weary spores back to life.
- Supplementing with complex carbs like bran gives starving mycelium a boost.
- Allowing more light, especially 6500k blue light, provides energy.
- Adding an air pump on a timer aerates the substrate fully.
- Using a clean SAB when handling substrate minimizes contamination risk.
- Seeking mentorship from an experienced cultivator lends expertise.
When to Start Over
While tweaking conditions and being patient is ideal, sometimes it’s better to cut your losses. Consider starting fresh with new spawn and substrate if:
- You see obvious contamination that cannot be fully removed.
- Spawn viability seems extremely low.
- Ideal conditions consistently fail to revive growth after 4 weeks.
- The substrate is hopelessly dried out with no progress.
By troubleshooting issues early and making adjustments, you can get your mycelium growth back on track. And remember, trial and error is part of the process – learn from each grow. With vigilance and patience, those fruits will flourish!
Frequently Asked Questions
Why is my mycelium not growing after two weeks?
The most common reasons are incorrect temperature, insufficient humidity, lack of gas exchange, contamination, poor substrate nutrition, or weak spawn health. Troubleshoot each factor systematically.
How can I accelerate mycelium growth?
Boost growth by ensuring ideal conditions, supplementing nutrition, using fresh viable spores, and introducing additional light. Avoid excessive handling or drying.
Should I start again if I see no growth after two weeks?
It’s best to thoroughly troubleshoot first. However, if conditions are ideal and there’s no progress after 3-4 weeks, it may be time to discard and restart with fresh sterile supplies.
Conclusion
Don’t despair if your mycelium growth stalls after two weeks. With systematic troubleshooting of conditions, contamination, nutrition, and spawn health, you can get your cultivation back on track. Adjust any factors found lacking, introduce helpful stimulation techniques, and allow more time before restarting as a last resort. Stay vigilant against contamination and keep environmental conditions optimized. With refined technique and persistence, your mycelium will thrive and fruits will flourish. Mush love!
The Wrong Environment
The key to learning how to grow mushrooms is to create an environment that’s conducive to the species that you’re cultivating. Make them feel at home!
That means don’t try to grow a warm-temperature mushroom in cold weather. Don’t try to cultivate a wood-loving species on straw. Make sure your mushroom substrate is nutrient-rich. Basically, give the mycelia what it needs to thrive.
Solution: Research. Know what kind of mushroom you’re trying to grow and what they need before you begin. You don’t have to read someone’s PhD thesis, but a little knowledge goes a long way.
Mushroom spawn that’s old or has traveled a great distance may not be as vigorous and may fail to thrive and produce. It’s no great secret that you should have the healthiest spawn possible to increase your chances of successfully growing mushrooms.
Solution: First off, only buy spawn from a reputable company. If you purchase from someplace sketchy with bad business practices you’ll get an inferior product. Ideally buy from somewhere close to you, so your spawn doesn’t have to go very far.
After that, the best advice is to use it or lose it! Don’t let spawn sit around forever, as it will weaken, create wastes, and possibly contaminate. Keeping it in the refrigerator will extend its life, but it becomes less viable with every passing week.
Not Enough Air Exchange
Mushrooms don’t need as much fresh air as we do, but they still need it. Without any air exchange carbon dioxide levels build up and your mushrooms will emerge as stunted, spindly things that are all stalks and no caps. Very disappointing.
Solution: Make sure your project has a flow of fresh air. Don’t place things in areas with no air exchange.
If you’re growing in a sealed environment, you may want to open it a few times a day for fresh air. Just be aware that when you introduce fresh air you also introduce the possibility of contaminants and lower humidity levels. It’s a delicate dance!