Lignicolous mushroom grain spawn on logs

Incubating logs with mycelium grain is also easy to use and gives a very good result for hobby growers! Because more species are available on grains than on plugs, you will be needing this technique.


  • freshly chopped piece of wood
  • chainsaw, hand saw or chisel and hammer
  • bag of fresh mycelium grain spawn
  • large plastic bag to put logs in after incubation
  • some tape to cover the holes


wood selection

1. Substrate selection:

Take a freshly chopped piece of wood of at least 10 cm diameter length from a deciduous tree. It needs to be freshly chopped wood of a healthy tree, as you want the log to be completely non-infected by funguses at the time of inserting the plugs.

At this stage, it is beneficial to leave the logs for two-three weeks, until the naturally occuring fungicides in the wood are gone.

How to make holes in logs for mushroom growing

2. Preparation:

Saw slots in the wood, not too wide, but nice and deep.

putting the spawn into the holes

3. Inoculation:

 Cut open the grain spawn bag and make slices the width of the holes. Stuff the grain spawn in the holes and cut off the leftover bits. You can re-use them in other holes. Cover the holes with simple tape or cool glycerin. Mice and rats love grain spawn.

incubating the logs of lignicolous mushrooms

4. Incubation:

Put the logs in a large plastic bag which is not hermetically closed and put it in a nice, warm and dark place at about 20°C until the mycelium has completely invaded your logs. The mushrooms will also grow if you put your log outside, but the process will be slower and in winter, growth may stop entirily. The incubation time depends on growing conditions, mushroom strain, type of wood and log thickness. Incubation for Pleurotus sp. (Oyster Mushroom), a fast grower, is between 3 and 6 months. For Lentinula edodes (Shii-take Mushroom) it is between 6 and 12 months.

If the environment is damp enough, you may consider not using plastic, but this needs to be considered locally. Some growers put their logs outside, stacked like pyramids, without any plastic. If you try this system where it is not damp, not shady and a bit windy, the mycelium will not grow properly.

Opening up the logs to full growth

5. Planting

Put the logs outside, in a damp and shady place. Dig small holes of 10 cm deep and put the logs with their feet in the ground. Remove the tape if it hasn't already fallen off. You don't have to dig them into the ground, but it helps keeping the humidity up. There are certainly other techniques to keep the humidity high, such as stacking them in pyramids in damp undergrowth, or covering them halfway with rotting autumn leaves. The choice is yours.


mushroom harvest from logs

6. Fructification:

Your mushrooms will start coming up as soon as the climatic conditions outdoors are right. The image depicts a flush of shii-take, which do very well on logs.

A good mushroom log can produce for many years, although the harvest gradually decreases (some Shiitake oak logs have been known to produce for 12-14 years in an outdoor environment!).