Caring for Mushroom Logs and Pit Spawn

Thanks to all those who have purchased mushroom logs.  I will continue to update this post with information on mushroom cultivation.

Markings on Logs/Quick Reference

P = Pioppino (Black Poplar Mushroom) – bring in during Winter – Fruits late summer/early fall

M =Maitake (Hen of the Woods) – buried – Fall fruiting

H = Shitake  – normal – Summer Fruiting

B = Blue Oyster – normal – Spring fruiting

K = King Oyster – normal – Spring Fruiting

G = Ghost (non-edible/bioluminescent) – bring in during winter– Fall fruiting

For those who purchased Pioppino (Black Poplar Mushroom) and Maitake (Hen of Woods) be sure to check the special notes for those species.

Edible mushrooms can be grown in many fashions.  Two common methods of cultivation are caring for mushroom logs and creating pits in the ground filled with mushroom spawn and substrate.


Caring for mushroom logs is moderately simple, the real task is their creation.  Although in theory one could simply leave the logs in a damp shady area and allow nature to run its course; supplemental care accelerates growth and ensures success.  Most of caring for a mushroom log or mushroom pit is choosing the location.

To care for a mushroom log begin by placing it in a shady area protected from strong winds.  Shade and protection from the wind are natural conditions found in a forest interior, these are the conditions many edible fungi thrive and the reason we imitate the conditions.  Usually the north and east of a structure are the best places in IL to find such a location.   You can prop your mushroom log up on the side of your house or a fence to minimize contact with the ground (see note on maitake logs below).  Minimize contact with the ground to reduce the chance of other fungi colonizing the surface of the log.  This is also the reason you don’t want to over the logs.  When I had fewer mushroom logs I would bury several rocks halfway in the ground creating a platform for the log.  The rocks also seemed to buffer changes in temperature.  However, it is important that the rocks do not get exposed to sun and heat.


Water your mushroom logs every so often, especially when there are times of drought or severe heat.  Use your shade plants as an indicator of  drought stress.  If your astilbe, coral bells, or other shade plants require water; water your mushroom log a bit.  Don’t over water.  The ends are the primary areas of water absorption, but also the areas that dry out fastest.  Every few months you can dunk your log in a 5 gallon bucket of water and allow to soak for several hours on each end.     Dunking your logs after a flush of mushrooms revitalizes the log and sometimes encourages a second fruiting.   If you have several logs, a clean garbage can or trough can be useful.

One special note for Maitake, Hen of the woods.  Its care is a bit easier.  It should be buried in a shady area with moist soil protected from the wind.

mushroom care

I have seen references to both horizontal and vertical burying of maitake logs. I have also seen references to both full and half burying of  logs.  All of this leads me to believe that orientation is not of the utmost importance.  I suggest full horizontal burying about 3 inches below the ground.  Mark the area with a garden sign.   Mulch with untreated hardwood the following spring and hope that this mulch gets infected with spores when your maitake fruit.

Winter care of mushroom logs.  Most species of mushroom logs can be left outside, however, bringing them inside gives extra time to grow and protects them from harsh conditions. Bringing your mushrooms in for winter and setting them outside again in the spring is a great way to jump start mushroom production.

**A note about Pioppino or Black Poplar Mushroom.  It should be brought in during the winter to ensure survival and accelerate growth.   Set it out again in the spring when temperatures are 50-60 degrees and the danger of  hard frosts have passed.

Pit Spawn / Mushroom Pits

Creating a mushroom pit is a bit more tricky but still simple.  It is the common method used to cultivate King Stropharia aka Winecap mushrooms.  Before you dig your hole you need to have a substrate ready.  The substrate will depend upon the species.  Many species like straw (Stropharia) or mulch (maitake).  Some species like straw mixed with dung (bitorqus).   The big decision to make when creating pit mushrooms is whether to use pasteurized substrate or raw substrate.

Pasteurization can be a tricky process and/or energy intensive.  There are several methods available for substrate pasteurization.  Most of these methods are difficult to recreate on a large scale or in the home.  Steam injection and hot water bathes are common methods; the substrate is heated at 160F for about 3 hours.   Large steam canning pots can be used for this process on the home scale.   Another method is soaking the substrate in weak lime water for a one or two days.   You can use large trash barrels or five gallon buckets for this process.  Drain afterward, this will ensure that the straw returns to a more normal pH of about 8, which is ideal for inoculation.

If you choose to skip the pasteurization step be more careful in choosing your substrate.  Straw should have been stored under ideal conditions and not previously exposed to moisture or mold.  Mulch is best if it is freshly shredded in the spring and allowed to cure about a week.  As with any mushroom and wood pairing; species must be considered.  Oak and hard maples great candidates for many species; they are non aromatic hardwoods.   Soak your mulch in water of a pH about 8 for about a day before use.

Next you will create your hole for the substrate and spawn to be introduced to.  Begin by excavating a hole in the ground at least 1.5 feet down.  Start by removing the litter on the surface and setting it aside.  This is to prevent the litter from mixing with the rest of the excavated soil or the introduced mulch.  Next sprinkle a small amount of spawn in the hole.  Then add a 2″ layer of substrate.  Then sprinkle with spawn.  Continue this process until the hole is about an inch above the surface.  The pit should settle over time to ground level or slightly above.  You may want to water your pit a bit as you install it, as you make your layers but do so sparingly, your substrate should already be moist from soaking.  If there are time of extreme drought the surface may need some watering.  However, over watering can promote contamination.

There are may more details in mushroom cultivation depending on species and substrate combination.  I will work on updating this and other posts regarding their application in permaculture e.g. Flamulina (the mulberry eater).

mushroom seasons