Best Time To Innoculate Mushroom Logs For Maximum Yield

The best time to inoculate mushroom logs depends on the climate and the type of mushroom being grown. For Shiitake mushrooms, the ideal time to fell trees for inoculation is during the winter and early spring when the trees are completely dormant. The logs should be inoculated within zero to two months of felling, with some sources specifying that the best time to inoculate is one month before the average last frost date, as long as daytime temperatures are above 40°F. In warmer climates, late winter or early spring is also recommended as the sugar content in the trees is highest during this period. The inoculation process involves drilling a series of holes in each log, inserting spawn into the holes, and then sealing the holes with wax. The type of spawn used can vary, with plug spawn being ideal for smaller projects or those who don't want to invest in equipment, while sawdust spawn is more suitable for larger-scale inoculations as it colonizes faster but requires additional tools.

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The best time of year to cut logs for inoculation

In fact, winter and early spring are ideal as they occur before leaf out and the spring sap movement and bud swell. Logs cut during this period can be stored for several months and still produce acceptable yields. However, it is important to note that the inoculation process should take place within zero to two months of the tree being felled, with the sooner the better for inoculation.

While it is possible to inoculate logs at any time during the winter months, it is crucial to avoid using logs that were cut prior to the summer months, even if they were cut while dormant. Logs exposed to warm weather conditions during the summer will not yield optimal results.

Additionally, logs should be selected from healthy living trees, with no rot at all. The optimum log size is typically 4-6 inches in diameter and 3-4 feet in length, with standard lengths making the inoculation process more convenient.

How to drill holes in logs for plug spawn

The process of drilling holes in logs for plug spawn is quite straightforward. Here is a step-by-step guide:

Selecting the Logs

Firstly, select the logs that are suitable for the mushroom species you want to grow. Logs must be cut from healthy living trees, with no rot at all. The best time of year to cut trees for inoculation is during the dormant season, from winter to early spring. This ensures the logs are in their best condition for mushroom cultivation.

Preparing the Logs

Before drilling, prepare the logs by removing all diseased and wounded sections, forks, crotches, and major kinks. Straight logs are easier to handle, but crooked logs can also be used. Remove small branches, leaving a stump of approximately two inches. Use a wire brush to clean the bark, being careful not to damage it, especially for thin-barked trees.

Drilling the Holes

Now, it's time to drill the holes. Use a power drill with a suitable drill bit for the size of your spawn plugs. Drill holes starting about one to two inches from the end of the log, spacing them about three to eight inches apart, depending on the log's diameter. The holes should be drilled in rows along the length of the log, with three to four inches between rows. The depth of the holes should be about 1.25 inches, or just enough to fully accommodate the plug spawn. It is recommended to drill a diamond pattern of holes to ensure rapid growth of the fungus throughout the log. However, some sources suggest that the pattern may not be as important as ensuring there are enough holes.

Clearing the Holes

After drilling, clear the remaining sawdust and woodchips from the holes to make room for the plug spawn. This step can be time-consuming, but it is essential to ensure a tight fit for the spawn plugs.

Waxing the Logs

Once the holes are drilled and cleared, coat the log wounds with wax to seal in moisture. This step helps maintain moisture in the log and creates optimal conditions for mycelium growth while reducing the risk of contamination by other fungi.

Inoculating the Logs

Finally, it's time to inoculate the logs with spawn. Use a hammer or mallet to gently pound the spawn plugs into the drilled holes. The plugs should be tight enough that they cannot be pushed in by hand but can be gently hammered in.

Remember, this process can be repetitive and time-consuming. It may be helpful to set up an assembly line or an inoculation table to make the process more efficient and comfortable.

How to drill holes in logs for sawdust spawn

Logs should be cut from healthy, living trees during the winter and early spring before the trees have budded out, and the bark is still holding fast to the trunk. The best time to inoculate logs is zero to two months from the date the tree was felled. Logs should be 4-6 inches in diameter and 3-4 feet in length. Logs with a thick sapwood layer and a small heartwood area are preferred.

To drill holes in logs for sawdust spawn, you will need a drill with a 7/16" (12mm) drill bit and an inoculation tool to pack the sawdust into the holes. You can insert sawdust by hand, but an inoculation tool will speed up the process and pack the sawdust more densely. If you are inoculating many logs, you can put an adapter on your angle grinder to make the work go more quickly and easily.

Drill holes starting one or two inches from the end of the log and spacing them three to eight inches apart. Make the rows of holes three to four inches apart along the girth of each log. For example, a four-inch-diameter log will have three rows of holes, with each hole in the line six inches apart. Drill the holes 1 1/4 inch deep.

The holes should be staggered in a diamond pattern to ensure rapid growth of the fungus throughout the log. Closer spacing increases the rate of colonisation and results in more rapid mushroom production; however, spawn costs are also greater. A general rule of thumb is to estimate the diameter of the log and have as many rows of drill holes as there are inches of diameter. For instance, a log with a six-inch diameter needs six rows. Plan for a minimum of 30 to 40 drill holes per log, depending on the log diameter.

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The pros and cons of using plug spawn vs. sawdust spawn

The best time to inoculate mushroom logs is during the winter and early spring before the trees leaf out. Logs should be cut from healthy, living trees and plugged within zero to two months, with the sooner the better.

Now, here are the pros and cons of using plug spawn versus sawdust spawn:

Plug Spawn

Plug spawn is easy to use and only requires common household tools such as a drill, hammer or mallet, and a paintbrush or wax dauber. It is in the form of wooden dowels inoculated with mycelium. However, it is more expensive than sawdust spawn and the inoculation process is slower. The mycelium also takes longer to migrate into the sapwood of the log. Plug spawn is typically used for smaller-scale operations.

Sawdust Spawn

Sawdust spawn is the preferred choice for most mushroom farmers or those who plant mushroom logs annually. It is the least expensive option and is commonly used for commercial enterprises. The mycelium in sawdust spawn moves out into the log more quickly, resulting in faster production. It is typically sold in special plastic bags with a filter patch to allow the mycelium to breathe while keeping out contaminants. However, sawdust spawn requires a specialised inoculation tool for insertion into the holes, which can be purchased or homemade.

How to prepare logs for inoculation

Preparing logs for inoculation is a crucial step in the process of growing mushrooms. Here is a detailed guide on how to prepare logs for inoculation:

Selecting the Right Logs:

Logs must be cut from healthy living trees with no rot. The best time to fell trees for inoculation is during the dormant season, particularly in winter and early spring before leaf growth. This ensures the logs are in optimal condition for mushroom growth.

Cutting and Preparing the Logs:

After selecting the right trees, cut the logs to your desired length, aiming for a diameter of 4-6 inches and a length of 3-4 feet for convenience and ease of handling. Remove all diseased, damaged, and forked sections, as well as small branches, leaving a stump of about two inches. Smoothen the bark using a wire brush to remove lichens and moss, especially important for thin-barked logs.

Drilling Holes for Inoculation:

Using a drill, create a series of holes in each log. For plug spawn, holes should be 5/16 inch in diameter and 1 1/4 inch deep, starting two inches from the end of the log and spaced 6-8 inches apart. For sawdust spawn, holes should be 7/16 inch in diameter and 1.25 inches deep, drilled 1 inch from the end of the log, with 3-4 inch spacing between holes. The number of rows of holes should correspond to the diameter of the log, creating a staggered diamond pattern to ensure rapid fungus growth throughout the log.

Inoculation Process:

The next step is to tightly pack each hole with spawn, either plug spawn or sawdust spawn. Plug spawn is simple to use and only requires a drill and hammer, but it is more expensive and slower. On the other hand, sawdust spawn is faster and cheaper but requires a special tool (inoculator) to insert the sawdust.

Sealing the Logs:

After inoculation, seal the holes and any wounds on the logs with wax. This helps create optimal conditions for mycelium growth and prevents contamination by other fungi. Wax over the ends of the logs and any areas where the bark was damaged or branches were removed.

With these steps, you'll have your logs prepared for inoculation, setting the foundation for a successful mushroom-growing endeavour.

Frequently asked questions