Inoculation of trunks and hives

Species of wood suitable for cultivation: oak and hornbeam (suitable for shitake), maple, poplar, alder, beech, birch, willow… (NOT conifers or fruit trees)

Mushroom yields are higher in harder woods (oak), while overgrowth is faster in softer woods (poplar). Wood harvested during the dormant season has the highest content of sugars and other nutrients and is therefore more suitable for mushroom cultivation. The yields are highest on such wood. Wood with as much sapwood as possible is also preferred, as it is easier for the mycelium to grow and decompose.

The surface of fresh tree trunks (6-21 cm diameter) is cleaned of lichens and other impurities. The trunks should be fresh, healthy and not cracked, and the bark intact.

Wood inoculation using mycelium on wooden plugs
Drill holes in the trunks in a ‘zig-zag’ pattern around the entire circumference (Figure 1, Fig. 1). The holes are drilled more densely at both ends of the branches, where side branches have grown out and around any bark damage. Insert mycelium-encrusted wooden plugs into the holes (Fig. 2). The holes should be 0.5 mm to 1.0 mm wider than the plugs (6.5 mm or 7 mm).

Insert the plugs fully into the holes. The number of plugs needed is given in Table 1. Coat the holes of the filled plugs with melted paraffin or beeswax (not with grafting resin!). The ends of the trunks are also coated to prevent the introduction of impurities and the evaporation of sap from the trunks (Fig. 3, Fig. 4).

Inoculating wood with mycelium on cereal grain
Cut the logs into short pieces (Figure 5), spread a layer of mycelium on cereal grain and fresh sawdust from sawing the logs over the whole surface (Figure 6). Protect the whole from drying out with food film (Figure 7, Figure 8) and coat the ends of the logs with wax or paraffin (Figure 2).

Mycelium on the cereal grain can also be stuffed into the V-shaped notches and then the cut-out part of the trunk can be inserted (Figure 9). If necessary, secure the cut part of the stem with a nail or screw and protect it from drying out with food film or polyvinyl (Figure 10, Sketch 3).

Place the mycelial trunks (inoculated trunks) in a shady place where they can be drenched by rain. However, care must be taken to ensure that water does not accumulate in the mycelium-filled notches, as this can rot the mycelium. If you see water accumulating under the foil, just gently peel it off. It is important that the trunks do not dry out, but at the same time do not get soaked (avoid places where there is water and strong winds). In places where the humidity fluctuates greatly due to sun, wind and rain, the bark starts to come off the trunks more quickly, allowing other organisms access to the wood (Figure 11) and reducing the yield of mushrooms.

Shady spots in the garden without direct sunlight are suitable. A sandy substrate is ideal. The trunks should be kept about 1 cm off the ground for the first six months of the year to prevent other unwanted organisms from entering them. Later on, when the mycelium has outgrown them, it is advisable to keep them in contact with the soil, as they can draw water from them during dry periods. In the open air, they should be watered in extremely dry weather.

Humid cellars (above 10o ^C) or rooms where the temperature and humidity fluctuations are less than outdoors are best suited for the regrowth phase (Fig. 12, Fig. 13). Such rooms allow the wood to grow through the winter. If mould appears on the trunks, the humidity is too high. In such a case, it is advisable to increase the ventilation, or to increase the room temperature. If the room is too dry, the trunks should be sprayed with water (Figure 14).

The regrowth process takes 9 to 18 months, and even longer for shiitakes. The rule of thumb for the overgrowth process is that the longer the overgrowth, the better it is for the fungi and their fruiting.
The mycelium can also be applied to the stumps. The following two methods are the most effective for this.

With mycelium on wooden plugs
Drill holes around the entire circumference of the hive, insert mycelium on wooden plugs (Figure 4) and protect from desiccation. In this case, it is best to use as many plugs as possible. Hives still oozing sap are not suitable for this purpose. If such a hive is to be used, it is best to allow it to dry out before inoculating it with mycelium.

With mycelium on cereal grains
The mycelium on the cereal grain is sprinkled over the entire surface of the cut part of the hive. It is advisable to spread a layer of fresh sawdust over the mycelium, on top of which the cut part of the hive is placed (Figure 5), and then protect the whole from sunlight and excessive drying with food film or polyvinyl (Figure 15, Figure 16).

To prevent drying out, it is advisable to cover the hive with polyvinyl and soil (leaves, straw, sand, etc.). The polyvinyl and soil should be removed after a few months when the hive is overgrown, but it is not advisable to do this during dry periods. Deciduous hives that do not ooze sap are best suited for this purpose, as excessive oozing of sap can cause mycelium to rot.