Submitted by Northspore Mushroom
Growing mushrooms on logs is an easy way to ensure you'll harvest mushrooms for years! After inoculation, logs are relatively low maintenance and you can grow several types of mushrooms in the same space.
Here's what you need to know to get started:
Select spawn
Source wood
Inoculation method
Maintenance and fruiting
Selecting your spawn
There are two styles of spawn we commonly use for growing mushrooms on logs: plug spawn and sawdust spawn. For smaller projects, or if you're not ready to invest in equipment, plug spawn is ideal. There are different-sized kits available to match your production goals. If you're inoculating more than eight logs or are looking to maximize efficiency, choose sawdust spawn. This spawn type colonizes about 30% faster than plugs but requires extra tools. One 5lb. bag will inoculate anywhere between 10-40 logs. (To get a more accurate idea of how much spawn, use the log inoculation calculator on the Northspore.com website.)
When choosing which mushroom to grow, it's important to know what tree species are in your area and what type of wood may be available. Most mushrooms grow well on a wide range of hardwoods, but a few are particular in their preferences. Finding the ideal tree species for your project will increase your chances of success and likely reward you with handfuls of mushrooms. Match your mushroom to the trees in our chart below.
Mushroom & tree species compatibility

Log inoculation
Healthy, living trees can be felled for mushroom logs nearly any time of year. It is not recommended to harvest logs during the spring between bud swell and full leaf out. During this time, most of the nutrients and energy of the tree are expended in a push to develop flowers and foliage, leaving little for fungal growth. Also, the bark is loose, increasing the risk of damage during cutting. Intact bark is very important for the spawn run. Never cut dead, dying, or diseased trees for mushroom growing.

Log size
Any size logs will work. You can use branches or saplings if that is what you have available. Small-diameter wood will colonize faster but produce for fewer seasons than a larger log. You also don’t want the logs to be so large or heavy that they are difficult to move. With the drilling method, a commonly used size is a 4-6’’ diameter with a 3-4’ length. For the pillar (aka totem) method, they can be up to a foot (or more!) in diameter and 6-18’’ high because they are moved less.We recommend sourcing logs from a sustainable forester or using sustainable practices in culling trees for mushroom production.
Methods of Inoculation
There are two main methods of inoculating: the traditional log method and the pillar (aka totem) method. The traditional method works well for most mushrooms that grow on logs and can be adapted to use on stumps, too. We can trace its use back thousands of years to modern-day Japan! The wonderful thing about mushroom logs is that you will get multiple years' worth of gourmet mushrooms without having to re-inoculate the logs. On average, a mushroom log produces for one year per inch of diameter of the log. So, if you inoculated a 5-inch diameter oak log with shiitake spawn, it will most likely produce for five years!
Timing your Inoculation
Logs should be inoculated within a week or two of cutting. This allows the cells in the tree to die but is not long enough for the log to dry out or for other competitor fungi to become established. One month would be the longest reasonable stretch between cutting and inoculating your logs unless it’s winter. When temperatures are consistently below freezing, the window for inoculation can be extended for several months. Freshly cut wood can be covered with snow to maintain moisture until you can inoculate in early spring.
Traditional Log Method
1. Use an 8.5mm or 5/16’’ bit for plug spawn or a 12mm or 7/16’’ bit for sawdust spawn and drill to a depth of 1’’ in a diamond pattern all over the perimeter of the log, omitting the cut ends. We recommend spacing holes four inches apart in rows staggered two inches apart.

2. Place plugs into your holes and use a hammer or mallet if the fit is snug. If using sawdust spawn, use an inoculation tool to push the sawdust spawn into the holes.
3. Brush melted wax over each plugged hole. Use a crockpot or an electric hot plate and a pot to melt the wax and a wool dauber or paintbrush to apply it. The double boiler method can also be used. Sealing the holes is critical to success because it protects the spawn from drying out and contamination. Cleaning the wax is basically impossible, so allocating a thrift store crockpot or bowl is a good idea.
Stump Method
Stumps take longer than logs to colonize but can produce for up to a decade.

Any size stumps can be inoculated, but they should be from freshly cut trees and in a shady environment. Make sure you can identify the stump and know what species of tree it is!
1. Girdle your stump by removing a two-inch wide band of bark, make sure to remove both the outer and inner layers of the bark. This helps to prevent suckers from growing.
2. Use a 8.5mm or 5/16’’ bit for plug spawn or a 12mm or 7/16’’ bit for sawdust spawn and drill to a depth of 1’’ all over the top, sides, and exposed roots of the stump.
3. Place plugs into your holes and use a hammer or mallet if the fit is snug. If using sawdust spawn use an inoculation tool to push sawdust spawn into the holes.
4. Brush melted wax over each plugged hole using the abovementioned method.
Pillar (aka totem) Method
In the pillar method, smaller sections of logs are stacked upright with sawdust spawn sandwiched between. No special tools are needed for this no-fuss technique and large-diameter wood becomes easy to use and attractive to display. This is the preferred method for oyster mushrooms, lion's mane, and reishi which naturally fruit when temperatures shift in the spring and fall. One 5lb bag of sawdust spawn should be enough to inoculate three or four 10-12" diameter stacks.
1. Cut three sections of log for each pillar: one piece only 2’’ long, and two sections 6’’ to

18’’ long.
2. Bring your supplies to your shady incubation place and create the pillars on site.
3. Lay a piece of brown cardboard or a kraft paper bag on the ground, sprinkle on a layer of sawdust spawn about 1’’ deep, and stand one of the 6’’-18’’ pieces upright on top of the spawn. Add another layer of sawdust spawn on top of this section and stand the next 6’’-18’’ section on top. Add one last layer of sawdust spawn on this section and then cap the pillar with the remaining 2’’ piece. Place an overturned paper lawn and leaf bag over your pillar. Tuck it under at the bottom or add weight to keep in place. The bag will help keep in moisture and keep out contaminants and pests.
4. Incubate the covered pillars for 4-12 months. The paper bag can be removed when the logs are covered with a visible layer of mushroom mycelium. The pillar can be left intact or broken up into individual sections for fruiting.
Trenching or burying your logs
Burying or partially burying logs is critical to successfully fruiting a few specific species because it provides additional moisture around the logs, creates contact with beneficial microbes in the soil, triggers fruit development, and limits light and oxygen to a smaller surface area.
We recommend burying or trenching hen of the woods, chicken of the woods,

chestnut, nameko and reishi logs after full colonization. One way to check if your log is colonized is by looking for mycelium on the ends of your logs. Mycelium does not always cover the entire end but should be visible on most of the end, either on the surface or under the wax. If no mycelium is visible you can use the average colonization time of the species you selected. If in doubt we recommend waiting approximately one year in areas with snowy winters while those in areas with mild winters could trench their logs after three seasons have passed. Keep in mind larger diameter logs will take longer to colonize.
In order to trench your logs, dig out an area half as deep as the diameter of your logs in a shaded location. Reserve the soil you remove from this area. Place your logs in your dug trench in a raft formation. Then take your reserved soil and pack it around and between the logs so only the top surface area of the logs are exposed. Wood chips or sawdust can be used in addition to or in place of soil for chestnut and nameko. Water the area so the material around your logs compacts and add more if necessary!
Post Inoculation
The time between inoculation and first harvest will depend on what species you’re growing, the size of your logs, and environmental conditions. Most mushrooms on standard size logs in temperate climates will take about a year to fully colonize before they fruit. This can vary between 6 months to two years. Smaller diameter logs and soft hardwoods will typically fruit sooner, though they’ll have less longevity.
Often, mushrooms need cool weather and moisture to fruit. Growth slows in the heat of the summer. If you inoculate in the spring, you might get your first flush of mushrooms in the fall but most likely it will take a full year until you see your first fruiting. If you inoculate in the fall and are able to keep the mycelium from going dormant, you may get mushrooms as soon as the next spring, though more likely the following fall.
Mushroom log yields depend on the type of wood chosen, the species you are inoculating, and environmental conditions. Generally speaking, dense hardwoods take longer to fully colonize but will continue to fruit for more years, while soft hardwoods (like poplar) will fruit sooner for fewer years. And wood with more sapwood than heartwood may yield more mushrooms.
Maintenance and Fruiting
Incubate logs in a shady place, close to the forest floor but not in contact with soil or leaf litter. There are a few different preferred methods. One is to lay down tracks of scrap wood that elevate the logs 1-2'' above the forest floor. Stack the logs in a layer with a little space for airflow between each log. If you have more logs, you can make multiple layers by off-setting each layer by 90°, log cabin style. Log cabin stacks can be as high as 5' in wetter climates, but in dry climates, shorter stacks are closer to the ground and help keep logs moist. Keep the stack lower than the average snow line, as the snow cover protects the logs from dry winter winds.
Generally, no special care is needed while the mycelium grows throughout the log, but watering may be needed if excessively dry weather occurs. Logs shouldn’t stay wet on the outside for long periods of time. Frequent light watering can even damage logs and cause contaminant growth. Long periodic soaking of no more than 24 hours is the preferred method of renewing water content should your logs appear dry or lose vitality.
About a year after inoculation, fruiting naturally occurs after big rains and occurs in cycles. After the log has fruited once on its own, it can be stimulated to fruit by watering or soaking it in cold water for no more than 24 hours. Force fruiting works best with shiitake mushrooms. Allow at least one month of rest before attempting to force fruit again. If it has recently fruited, forcing will probably not work.
Conclusion
Growing mushrooms on logs, totems, and stumps is a rewarding and sustainable way to provide you and yours with a seasonal but continuous supply of gourmet mushrooms. By carefully selecting spawn and wood, using effective inoculation methods, and maintaining optimal conditions for colonization and fruiting, you’ll have multiple mushroom harvests over many years. Whether you choose the traditional log, stump, or pillar method, each approach offers unique advantages and flexibility and with minimal maintenance and proper timing, your mushroom logs can produce bountiful harvests, making this an accessible and enjoyable endeavor for both novice and experienced growers alike.
Reprinted with permission from northspore.com
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