Spawn Run & Incubation
26
to set up, and only recommended
for steep hillsides. is technique
creates a very stable, aerated stack in
which mushrooms are highly visible
and easy to pick. e majority of
logs are also raised o the ground,
potentially reducing slug damage.
Moisture Management
It is important to ensure that the
logs stay moist during the incuba-
tion period. Shiitake spawn cannot survive in logs that have a moisture content
(the amount of available water in the log, expressed as a percent of the fresh
weight) of less than 23 percent. Ideal moisture conditions for shiitake growth
are log moisture content is 35 percent or more.
Keeping the logs shaded during the warm summer months will help main-
tain higher levels log moisture. Keeping logs shaded or snow covered during
winter will ensure that the typically dry winter air does not dry out the logs.
An evergreen canopy will shade the logs year-round. A thick deciduous canopy
during the summer months will generally suce, but a shading strategy needs
to be employed for months with no leaf cover.
is can vary from a structure
covered with shade cloth (70 percent),
or simply by covering the logs with
shade cloth. Professional greenhouse
shade cloth is ideal, but burlap will
suce. Do use an opaque covering. If
shade cloth is draped over crib stacks
during winter, care should be taken
to remove shade cloth when tem-
peratures rise in the spring, to avoid
drying and encouraging competitive
fungi to grow under the cloth or tarp.
In addition to keeping the logs shaded, you may want to consider dousing
them with water occasionally during warm, dry summer month. is could
be accomplished either using a simple hose and sprinkler system or a good
soak for at least several hours is generally enough. If the logs are primed this
might actually trigger a ush, so keep an eye on them aer soaking. Expert
growers recommend limiting maintenance soaks to no more than two hours.
See sidebar on le.
It can be dicult to know when to initiate a maintenance soak. You can
measure the moisture content of the log by cutting o a section of the log
(known as a cookie), weighing it, drying it over 12 hours, and reweighing
it. e moisture content of the log will be equal to the weight of water that
evaporated during drying (wet weight minus dry weight), divided by the wet
“As a rule of thumb I would recommend
2 maintenance soaks during the initial
spawn run. A minimum soak of 2 hours
for all logs in the spawn run in early July
and mid-August should keep your shii-
take mycelium humming along nicely
in most years.
“If your logs from last year are quite a
ways from forcing I certainly would give
them a maintenance soak during long
bouts of hot dry, hot weather. My own
yard is very protected from wind and
direct sun so I don’t worry much about
maintenance soaks especially once
I have started forcing cycles in early
June. However, if your laying yard is less
than ideal with sun and wind factoring
in more, you may want to do a mainte-
nance soak ... but do keep these soaks
very short (1 to 2 hours) to not trigger a
ush. When logs are 4 weeks out from
a forcing, I empty my soaking tanks
weekly on stacks (buckets of water
method) that are a month away from
a forcing to give them an articial rain
shower. My soaking tanks hold about
12 to 14 logs comfortably so it is a good
way to hydrate logs quickly if I am in the
yard for a few hours. “
- Steve Sierigk, Hawk Meadow Farm
“We have never done maintenance
soakings. We have used sprinklers once
in 5 years. Too many other things to do
and too many logs! Maybe some logs
have dried out earlier than they might
have otherwise. Hard to know. We get
three good years out of our logs, two
ushes a season.”
- Steve and Julie Rockcastle,
Green Heron Growers
EXPERT OPINION: Maintenance Soaking
For more information on this stack-
ing method see “Our Cultivation
Guide” featured on the Northern
Mushroom Growers website at http://
mushrooms.cals.cornell.edu/.
EXPERT TIPS: Hillside Stack
(Drawings by Carl Whitaker)
Log shaded by an structure covered in shade cloth.
(Bill Stack, Cobb Hill Farm