Log Cultivation for Outdoor Gardens
Grow Mushrooms Outdoors on Logs
Log Cultivation for Outdoor Gardens
Grow Mushrooms Outdoors on Logs
Growing mushrooms on logs offers a sustainable and rewarding
way to cultivate mushrooms over the long term. This method
utilizes hardwood logs inoculated with plug spawn—small
wooden dowels infused with mushroom mycelium—that
gradually colonize the log.
Once fully colonized, the log becomes
a natural substrate for the mushrooms, producing reliable
harvests year after year. This approach mimics the fungi's natural
growth environment, requiring minimal maintenance while
providing consistent yields and a connection to nature's cycles.
Grow mushrooms sustainably with our log kits for outdoor gardening.
Mycelium vs. Mold
Mycelium vs. Mold
Healthy mycelium (pictured) is typically fluffy and white or off-white. Your plug spawn will likely appear similar to what is pictured, but the dowel appearance may vary slightly as a fluted or spiral cut dowel.
Mold will typically appear as a green, black, or even orange substance, making it hard to mistake. If you see mold in your plug spawn, consider replacing your spawn or contacting our support team.
Log Selection & Care
Fresh hardwood logs are ideal for growing mushrooms. Suitable species include oak, maple, beech, and alder. Avoid softwoods like pine, cedar, and spruce.
Shiitake: Alder, Beech, Ironwood/Hophornbeam, Hornbeam, Oak, Sweetgum
Logs should be 3-6 inches in diameter and 3–4 feet long. These dimensions are manageable for moving by hand for most and provide ample material for repeated yearly harvests.
Logs should be cut from healthy, live trees no more than six weeks before inoculation. Avoid logs with visible signs of decay or rot.
Healthy, living trees can be cut for mushroom logs at nearly any time, but the best windows are:
- Late winter to early spring before bud swell
- Fall after one-third of the leaves have changed color.
- For logs harvested early in winter, protect them from drying out by shading or covering until temperatures rise above freezing
During these times, nutrients are concentrated in the wood, and the bark remains tight, protecting logs during the spawn run. Avoid cutting logs in spring after budding, as nutrients are used for foliage growth, and bark can loosen, increasing contamination risks.After cutting, allow logs to cure for at least two weeks before inoculation to let antifungal compounds subside..
Logs should remain moist throughout colonization. During dry periods, water the logs lightly with a hose or sprinkler to maintain humidity without oversaturating them. You can also use a plastic sheet to help maintain moisture levels.
After colonization is complete (6–12 months), soak the logs in cold water for 12–24 hours to stimulate fruiting. This mimics the conditions of natural rainfall.
Logs can withstand freezing temperatures during colonization. However, ensure they are not waterlogged before freezing to avoid damage.
There are several techniques for log stacking, and while the best method can depend on your harvest preference and the natural growth patterns of the mushroom, there are some tricks to stacking incubating logs and logs that are ready to fruit.
For incubating logs, stack logs on top of a pallet (or set of logs that have not been inoculated) in a single layer, then stack a second layer perpendicular to the first. Repeat until the stack is a few feet high.
When you're ready to fruit your logs, consider using a log-cabin style pattern (square with open center), lean-to, or A-Frame stack to improve airflow and promote fruiting of soaked logs.
Plug Spawn
Plug spawn can be stored for up to six months if kept under appropriate conditions.
Store plug spawn in a cool, dark place, such as a refrigerator, and keep it sealed to maintain its viability.
The kernels are bits of grain included with the plug spawn to support mycelium growth. They are normal and should not affect inoculation.
We offer plug spawn in 3 species - Lion's Mane, Blue Oyster, and Shiitake. Each kit contains approximately 100 colonized plug spawn with the species of your choice.
Healthy mycelium is fluffy and white or slightly cream-colored. Mold is usually green, black, or orange, with a cotton-like or clumped appearance. If you see mold, consider replacing the spawn.
Inoculating Logs
You will need:
- RMS Log Cultivation Kit
OR
- a 5/16-inch drill bit
- Plug spawn (about 40 dowels per 3' Log)
- Hammer or mallet
- Wax (soy or paraffin)
- Brush or applicator for the wax
AND
- A heat source to melt the wax (hot plate or crock pot)
- Hammer or mallet
- Power Drill (Corded or high-power cordless)
- Clean and prepare log surface by removing moss or lichen - try to keep any bark intact.
- Drill holes 1 inch deep and 4–6 inches apart in a diamond pattern around the log.
- Insert plug spawn into each hole and hammer them flush with the log's surface.
- Seal the holes with melted wax to protect the mycelium and prevent contamination.
Soy or paraffin wax is recommended. Both are effective in sealing inoculation sites to retain moisture and protect against contamination. Beeswax and other waxes are prone to cracking or chipping during temperature swings and rough handling, which can expose your mycelium to pests.
Generally speaking, heating wax is easy, but requires some caution. We recommend using a double boiler, small crock pot, or a hot plate to melt your wax. If you must use open flame to heat wax, use caution and do not spill the wax onto the element or outside of the vessel, as most waxes are flammable.
For our kits, we recommend using a 5/16" size drill bit. There are specialized drill bits with "stop collars" available as well. You can make your own stop collar by putting a piece of tape at the 1" mark of your drill bit from the tip as a visual indicator on where to stop when drilling.
Once you've inoculated your logs, place them in a shady area for incubation such as beneath a tree for 6-12 months. It's recommended to stack your logs on a "sacrifical" pallet or layer of logs. Stack a layer on top of the pallet, then a cross layer on top, repeating until it is a few feet high at most. You can cover your logs with a plastic sheet maintain moisture, or give a light watering if they appear dry.
Harvesting Mushrooms
Colonization typically takes 6–12 months, depending on the mushroom species and environmental conditions. Faster-growing species like oysters may be ready in six months, while shiitake can take up to a year.
A well-maintained log can produce mushrooms for several years. The yield will vary depending on the species, log size, and conditions, but can range from ¼ - ½ pound per inoculation site.
Once you've incubated for 6-12 months, you can dunk your logs in cold water and soak them for 24 hours to simulate rainfall. Then, stack in a log cabin (open square) style formation, lean to, or A-frame to allow for more airflow and stimulate fruiting body growth.
Logs can produce mushrooms for 3–7 years, depending on the species and the type of wood used. For hardwood species, a good rule of thumb is 1 year per inch of log diameter.
Once colonized, mushrooms will fruit during favorable seasons, typically in spring or fall, when conditions are cool and moist.
Common pests include slugs, insects, deer, and rodents. Regularly inspect logs and address pest issues by improving airflow, reapplying wax, or adjusting stacking methods. If necessary, use preventative pest measures designed to repel the pest you are dealing with.
