PRODUCTION SITE

The laying yard is your mushroom production site (Figure 1). A laying yard should be under forest canopy and in a location that protects your bolts from direct sun, and winds. Similar to the inoculation station, the laying yard also needs some forethought to keep production efficient and any hazards minimized. The laying yard needs to accommodate bolts that are “at rest” during spawn run and between fruitings, tanks for soaking bolts for forced fruitings and bolt moisture recharge, and support structures for putting bolts that are being fruited for harvest into an A-frame formation. The laying yard site also has a few potential deal-breakers for growers interested in establishing a forest-cultivated mushroom system, 1) whether you have an appropriately well-shaded forest location, 2) whether you readily get your bolts there from your inoculation location, and 3) whether you have feasible access to water at/near your site that can be used for soaking bolts in the production process. Generally the laying production space required is relatively small compared to most other outdoor farming enterprises. Depending on site restrictions and the number of soaking tanks, each 100 bolts should generally not require more than 480 sq.ft of production space (see example in Figure 5).

Siting your laying yard:

Places with water bodies or wetlands nearby (Figure 2C) are ideal for facilitating a more humid microclimate (don’t put your laying yard in a wetland), and north-facing slopes and tall evergreens along the south edge of the laying yard help block direct sun throughout the year. Strive to leave as much vegetation in-place as within the laying yard as long as it’s not logistically burdensome to efficiently get around your laying yard as you need. Sometimes even a single branch can make a big difference in providing some critical shade and/wind-blocking if you’re able to work around it. You always also have the option of temporarily tying back branches that are otherwise difficult to work around while working in your laying yard. Also account for the changes in the sun’s path throughout the year. Note that evergreens can have a moderate “umbrella effect” by intercepting some of the rain that otherwise would get to your bolts in winter, so if possible, locating your bolts just outside their drip line area can allow more moisture-replenishing rain to reach your bolts in the off-season.

Another very important thing to consider your access to water at the site. Because soaking the bolts is a critical component of using this system to produce shiitake for market, water access is key. Not having water access at your laying yard effectively renders this production system to be non-viable for commercial production contexts. If 100’ of garden hose can’t get your site connected to a pressurized water spigot, a 500’ run of 5/8 black poly tubing is a reasonably affordable option for getting water to your laying yard, provided the water pressure is ample to get your water there. If pressure is an issue, you could consider an electric water pressure booster at the source. Other options are running a pump from a creek or other surface water body, or a using a large tank that can be brought by truck or tractor to the laying yard, though some people may find both of these options to be too costly or inefficient.

Crib stack area:

Crib stacks are a space-efficient and way to organize your bolts in your laying yard during the spawn run period or any other time the bolts are not actively being fruited (“rested”). The alternating perpendicular layering of crib stacks allows more bolts to be stacked into a unit of area without needing any vertical supports on the sides of the stack (Figure 3). Bolts that are all tightly stacked parallel to each other (like firewood) cannot be stacked as high, but have an partial advantage regarding discouraging moisture loss from the bolts. Stacking like this is alright during the early period part of spawn run (until late spring), but a longer-term downside of parallel stacking is that the shiitake fungus can grow between bolts as spawn run progresses. This can causing bolts to stick together enough that the bark can get ripped off when you try to separate them. The alternating perpendicular pattern reduces the contact points between bolts, and hence reduces opportunity for the bolts to fuse together.

Typically, you may be able to fit a minimum of 6 bolts per layer, 4 layers deep, for a minimum total of 24 bolts per stack. Each stack is placed on a shipping pallet to keep bolts off of the forest floor. This helps discourage other fungi and dampwood termites from getting into the bottom layer of bolts and compromising them. On hillsides, you can put supports under the downhill side of the pallets to get them level, and/or you could choose to terrace the forest floor as a long-term investment in your laying yard. Placing larger bolts on the outside edges of the stack helps keep the stack stable. This also keeps the smaller bolts that are may be more vulnerable to drying more protected within the inner parts of the stack.

Space your crib stacks close together wherever you don’t need to fit in between them to access another part of the laying yard. Leave ~18-24” in between stacks for access paths where needed to walk through. Two closely-spaced stacks will allow access to all bolts from three sides. Stacks placed closely together help somewhat with bolt moisture retention, and helps the stacks support each other.

Soaking tank area

Your soaking tanks are an integral part of a laying yard; keeping them on-site means the distance required to move the bolts from crib stacks into the tanks is minimized. Having your soaking tanks off-site will vastly increase the inefficiency of your system. The tanks used for soaking should be able to efficiently accommodate the full length of your bolts, meaning that the bolts are able to fit into as much of the available tank space as possible, and reduce how much water is required to fill the tank. They also need to accomodate a means to keep the bolts from floating, so that the bolts can remain fully immersed throughout the soaking period. In Japan, soaking tanks used for larger scale forest-cultivated shiitake are often permanent concrete tanks that re recessed into the ground, and are large enough to fit an entire crib stack’s worth of bolts that can be lowered in all at once by a hoist. These types of soaking tank setups are likely cost-prohibitive for beginning and smaller scale forest-cultivated shiitake producers in the PNW. The more accessible soaking tank option for growers are 2x2x6’ galvanized steel stock tanks. Although these tanks have 1’-long rounded ends of unnecessary tank space, there is a 4’ straight section which accommodates the full length of a bolt from the top to the bottom of the tanks. These types of tanks also have a lip along the top of the tanks that two boards can be fitted under perpendicularly to keep the bolts below the water line. The ground where your tanks are placed should be as level as possible to allow you to fill the tanks to the brim if needed. You may also opt to connect a hose to the drain port on the tanks for when the tanks are drained to avoid erosion in the laying yard and to be able to position the drain water to a location that can handle the volume of water that is drained from them. If possible at your laying yard site, it is advantageous to situate your crib stacks in a line, then situate your tanks in an adjacent line, and then your A-frame supports in a line adjacent to the soaking tanks. This will make the system very efficient from a logistical/ergonomical standpoint. With the soaking tanks in a line in the middle of the yard, bolts can then easily moved into and out of the tanks from either the crib stacks or the A-frames.

It helps to be strategic with any water lines you use to get water to your tanks in laying yard; 1) route them to be out of the way and at risk of damage, 2) if a line can be run downhill, this will help with maintaining water pressure, and 3) if lines can be either elevated or buried this may help logistically depending on your situation. Having lines elevated (tethered to trees or posts) may help leaks to be visible (including leaks resulting from animals chewing the line). Elevating the line is also fairly easy work-wise. Alternatively, although it’s more work, burying lines can protect them from damage, get them out of the way, logistically, and will also importantly help water in the line cool, which is beneficial for more effective forced-fruiting of shiitake.

A-frame area:

The A-frame area is where your bolts will be placed after soaking for forced-fruiting, and throughout the fruiting and harvest period(s). In your initial year of production during spawn run, you will not be using this area, but you will still need to allot space for this area in your laying yard site plan. This area consists of space for a central A-frame support beam, and 2’ of ground space on either side of the A-frame support beam. The A-frame support beam is a simple straight, rigid length of lumber (such as a standard 2x4”) or other rigid material fastened ~3-3.5’ above the ground onto two posts in the ground on either end of the beam. For fruiting and harvest, bolts are leaned against either side of the A-frame support beam; in order for the bolts to not fall over (vertically), the base of the bolt needs to be placed on the ground 1-2’ out from the A-frame support beam, hence the need for 2’ of ground space needed on either side of the A-frame support beam (Figure 4). To help prevent bolts from falling laterally (i.e. causing a domino effect that knocks all the adjacent bolts over) 18”-long cross beams can be screwed into the bottom of the beam on either end and every 2.5’ along length of the beam. A 10’-long A-frame beam should be able to support the weight of at least 25 bolts without the need for any other support posts in the middle of the beam, and is long enough to space 25 bolts sufficiently apart to allow for mushroom growth and good harvest access. This length of beam also matches a single crib stack’s worth of bolts, and is approximately two soaking tanks-worth of bolts (though a single tank may be able to fit up to 16 bolts or more, depending on size). Plan on leaving at least 1.5-2” on all sides of the A-frame to allow you to access each side of the A-frame as needed during setup and harvest. Similar to other areas of the laying yard, the A-frame area should ideally be protected from direct sun and wind as much as possible.