How to Grow Mushrooms on Logs: A Beginner’s Guide to the Plug Spawn Method

February 10, 2025

If you've ever wanted to grow your own mushrooms at home, the plug spawn method is one of the easiest and most rewarding ways to get started. Growing mushrooms on logs using plug spawn allows you to cultivate delicious, gourmet varieties like shiitake and oyster mushrooms with minimal effort. Whether you’re a gardening enthusiast or a complete beginner, this guide will walk you through the entire process from start to finish.

What is Plug Spawn?

Plug spawn consists of wooden dowels infused with mushroom mycelium, which is the vegetative growth of fungi. The above image of our homemade Lion's Mane plug spawn, and it is still in its vegetative state after being in the dark. When inserted into logs, the mycelium gradually colonizes the wood, eventually producing mushrooms. This method is popular for its simplicity and effectiveness, especially for beginners.

Benefits of Plug Spawn:

Low maintenance compared to other growing methods
Produces mushrooms for multiple years
Sustainable and eco-friendly
No special indoor growing environment required

What You'll Need to Get Started

Before you begin, gather the following supplies:

Fresh Hardwood Logs (Oak, Maple, Beech, or similar)
Healthy Plug Spawn (shiitake, oyster, or other mushroom species) Amazon is a great source for these!
Drill (with a 5/16-inch drill bit)
Hammer or Mallet
Wax (cheese wax or beeswax)
Paintbrush or Wax Applicator
Outdoor Space for Incubation

Step-by-Step Guide to Growing Mushrooms on Logs

Step 1: Selecting the Right Logs

Choosing the right type of log is crucial for successful mushroom cultivation, and its always best to inoculate your logs in the late winter months.

Best Types of Wood: Hardwood species such as oak, maple, and beech provide a nutrient-rich substrate that supports fungal growth. Avoid softwoods like pine, as they contain resins that inhibit mycelium growth.
Log Size: Logs should be around 3-8 inches in diameter and 3-4 feet long, making them manageable for handling.
Freshness Matters: Use freshly cut logs that are less than 2 months old, as older logs may already be colonized by wild fungi. You can inspect the log to see if there is any active fungal growth in the rings before using.

Step 2: Drilling Holes for Plug Spawn

Using a 5/16-inch drill bit, drill holes spaced about 6 inches apart in a diamond pattern around the entire log. Drill each hole about 1.5 inches deep to allow for proper insertion of the plug spawn.

Pro Tip: Mark the log before drilling to ensure even spacing and better colonization.

Step 3: Inserting the Plug Spawn

Once the holes are drilled, insert the plug spawn dowels into the holes one by one. Use a hammer or mallet to gently tap them into place until they are flush with the surface of the log.

Step 4: Sealing with Wax

To prevent the log from drying out and to protect the spawn from contaminants, seal each hole with melted wax.

How to Apply Wax: Melt the cheese wax or beeswax in a pot and use a paintbrush to cover each plug securely.
Additional Sealing: Wax any exposed cut ends of the log to reduce moisture loss.

Step 5: Incubation and Colonization

After sealing, place the logs in a shaded, humid outdoor area, such as under trees or next to a building. Logs should be kept off the ground (using bricks or pallets) to avoid competing fungi and pests. Alternatively, you can bury 3 inches of the log in sand to keep it moist for year round harvesting.

Ideal Conditions: Keep logs in a humid environment with regular rainfall or occasional watering if dry.
Colonization Time: Depending on the mushroom species, colonization can take 6-12 months, during which the mycelium will spread throughout the log.

Step 6: Encouraging Fruiting

Once the log is fully colonized, you’ll start to see mushroom growth, usually after a soaking rain or when humidity levels are high. To initiate fruiting:

Soak the logs in cold water for 24 hours to stimulate mushroom production.
Stand the logs upright and bury the bottom 3 inches in wet sand, or lean them against a surface to allow proper airflow.
Maintain moisture by misting if conditions are dry.

Step 7: Harvesting Your Mushrooms

When your mushrooms begin to appear, allow them to grow until the caps fully expand but before they start to flatten out. Use a sharp knife to cut the mushrooms at the base.

Harvesting Tip: Pick mushrooms regularly to encourage continued production and prevent overgrowth.

Step 8: Ongoing Care and Maintenance

With proper care, mushroom logs can produce for 3-5 years, offering multiple harvests per year.

Keep logs moist: Regularly water them during dry spells.
Protect from pests: Check logs for signs of mold or insects and move them if necessary.
Rotate logs: Occasionally change the positioning to ensure even colonization.

Common Mistakes to Avoid

Using Old or Rotting Logs: Always use fresh logs to prevent contamination.
Drying Out Logs: Mushrooms need moisture—ensure logs are watered if conditions are dry.
Not Allowing Enough Time: Colonization can take up to a year; be patient for best results. The health of your plug spawn also has a lot to do with colonization times.

Best Mushroom Varieties for Log Cultivation

If you're unsure which mushrooms to grow, here are some beginner-friendly options:

Shiitake: One of the most popular log-grown mushrooms, known for its rich, earthy flavor and high yield.
Oyster Mushrooms: Fast-growing and versatile, oysters thrive on a variety of hardwood logs.
Lion's Mane: Unique in appearance and known for potential cognitive benefits.

Frequently Asked Questions

Q: How long does it take to see mushrooms?
A: Colonization typically takes 6-12 months, with fruiting cycles occurring in cooler, wetter seasons.

Q: Can I grow mushrooms indoors using logs?
A: While possible, logs require high humidity and airflow, making outdoor locations more suitable.

Q: How many times will the log produce mushrooms?
A: Logs can provide 3-5 years of harvests with proper care.

Conclusion: Start Growing Your Own Mushrooms Today!

Growing mushrooms on logs using the plug spawn method is a simple, sustainable, and rewarding way to enjoy fresh fungi at home. With the right preparation and care, your logs can provide delicious mushrooms for years to come. Whether you're looking to expand your gardening skills or try a fun DIY project, this beginner-friendly method is the perfect way to get started. Here is a troubleshooting guide if you have any trouble along your experience.

Ready to grow? Start gathering your materials and enjoy the journey of homegrown mushrooms today!