Fruiting & Harvest Gallery
Figure 1. The images depict various shiitake fruiting interactions with the bark of the bolt. Image (A) depicts a very early stage of fruiting on a red alder bolt where primordia forming on the mycelial mat beneath the bark are apparent as raised bumps, and where one primordium has successfully broken through the bark (yellow circle, image A). Image (B) depicts the “pinning” stage where mushroom growth shows early formation of a cap; most pins on this birch bolt are constrained to exiting through the inoculation holes in the bark (white circles, image B), but one pin is struggling to grow through the tough birch bark (yellow circle, image B). Image (C) further illustrates how shiitake primordia can struggle to grow out of the mycelial mat and through the bark on bolt species like birch and cherry that have high tensile strength. Image (D) illustrates that even on bolt species with more brittle bark like red alder, mushroom caps can sometimes be deformed in the process of breaking through the bark. Image (E) illustrates highly constrained fruiting a cherry bolt, where four mushrooms have been forced to exit through a single inoculation hole. Image (F) shows a rare phenomenon where a mushroom has emerged from a section of a bolt where the bark has been damaged by animal pests; this likely occurred because garry oak bark is very thick, leading to enough of the bark remaining in-tact to keep the mycelial mat from being completely compromised.
Figure 2. The images illustrate the degree of variability in mushroom harvest ripeness that may be observed at a given moment on bolts that have all been soaked for fruiting at the same time. Image (A) shows variability of fruiting the same strain but different bolt wood species (birch bolts to the left, maple bolts to the right). Image (B) depicts the fruiting variability across bolts of the same species (red alder), but each bolt being a different shiitake strain. Image (C) depicts variability in fruiting across bolts of the same wood species and strain.
Figure 3. The images depict variability in shiitake mushroom cap “fringing” and other cap aesthetics that may be observed across various strains, bolt species, and fruiting conditions. The white frost-like “fringing” on a shiitake mushroom may be more constrained to the cap edges such as illustrated in images (A), (D), and (E), or may be more dispersed such as illustrated in Images (B), (C), (F), and (H). Mushroom of the same strain (images C, D, F, G) can vary in appearance in accordance to different growing conditions and bolt species, including fruiting in cooler weather (image D) which tends to produce more constrained fringing near the edges, and dry weather during fruiting, which will affect cap color and fissures in the cap (images F and G). The range of variability in shiitake cap color can be seen between image (G) and image (H), as affected by strain, bolt species, and weather conditions during fruiting. Bolt species that are more readily water-absorbent such as red alder may commonly produce darker colors (image H), whereas, bolt species that are more resistant to water absorption may commonly produce mushrooms with caps that are lighter colored (images E and G). Some strains may retain a more strong aesthetic character than others (images A and E) despite other factors that may typically influence appearance.
Figure 4. Shiitake stem and related phenomena are illustrated in the images. Multi-stem clusters that such as shown on this this western beaked hazel in image (A) appear to be most related influenced strain, but also appear to occur often when fruiting on hazels (Corylus species, such as shown here). Stem size (and length), and consequent mushroom growth potential (image B) appears to also be heavily influenced by strain but also by the age of the bolt; the stem size and mushrooms shown in image (A) are depict the first fruiting off of this particular bolt. Fruitings with stout, stem-heavy mushrooms are not uncommon from the initial fruiting(s) from a bolt in general.
Fruiting/mushroom variability and potential causes:
Thin stems, small mushrooms – mushrooms on older bolts, strains growing at the upper end of their fruiting temperature range, wood species with bark that is easy for the mushrooms to grow through, and strain character (to a degree)
Thick stems, large mushrooms – mushrooms on younger bolts (Figure 4A), strain (Figure 4B), when fruiting on a bolt is limited to few mushrooms, and/or where fruiting is highly constrained to the inoculation holes due to tough bark
Thin caps – older bolts, strain, strains growing at the upper end of their fruiting temperature range, mushrooms in the waning stage of growth
Thick caps – mushrooms on younger bolts (Figure 4A), strain, strains growing at the lower end of their fruiting temperature range, mushrooms in the waxing stage
Aborted mushrooms (mushrooms that don’t grow beyond the pin stage)– excessive dryness, strains being fruited near their lower fruiting temperature threshold, possible incomplete spawn run or bark restricting mushroom growth
Deformed/irregular caps – mushrooms that pushed through bark (rather than growing out of the inoculation holes; Figure 1D)
Differences in cap “fringing” (the white, “frosted” fuzzy growth along the cap edge) – largely due to strain character, but also growth at the lower end of their fruiting temperature range tends to produce more dense fringing for a given strain
Differences in cap color – strain character, humidity during fruiting, wood substrate species and plausibly how much moisture a given wood species can provide during fruiting (Figure 3)
Double stems/caps – Physiological anomaly, strain character, wood substrate species (Figure 4A)
Pale color – Mushrooms fruiting in dry conditions, or on bolt species that are relatively resistant to absorbing water during soaking (Figures 3F, 3G)
Figure 5. The images show common pests of shiitake mushrooms observed in the PNW. Images (A), (B), (C) and (D) show minor pests that may be found in the gills of unprotected shiitake mushrooms; these pests are unlikely to cause significant damage, but are unappetizing to your market nonetheless. Image (E) of an isopod (AKA pill bugs, sow bugs, etc.) and (F) of a millipede eating their way into mushrooms illustrates what has been observed to be the most commonly damaging pests in the PNW, should they make it inside your fruiting tents. Isopods in particular will leave visible feces as they eat (illustrated in image E), making the mushroom additionally unmarketable. Even one or two of either pest inside a fruiting tent can lead to damage on multiple mushrooms. Isopods in particular are very quick to find their way into an opening in the fruiting tent. Slugs can also cause similar types of damage along with a distinctive slime trail and fecal residue (image G), but are less likely to get inside a fruiting tent than isopods or millipedes.
Note on forced fruiting using municipal water: Any effects of chlorine-treated municipal water have not been formally evaluated. Many mushroom-growing enthusiast websites caution against using municipal water because chlorine itself is capable of deactivating fungal mycelium, but the levels used in drinking water are relatively low, in perspective. Drinking water chlorine levels (up to 4 ppm) are targeted at being effective against a suite of certain pathogenic microorganisms (bacteria, viruses, protozoa), rather than fungi, which have been found to be relatively resistant to deactivation at that those levels. Further, chlorine in water will be deactivated in accordance with the levels of organic material in the water (i.e. the dirtier the water is, the more chlorine is needed to be effective). For example, the maximum concentration of chlorine used in municipal water is 12.5 to 50x lower than the concentrations needed to be effective for washing produce after a pre-rinse to remove soil or other organic debris. Chlorine also begins evaporating once it is in the open, and will dissipate from drinking water within 24 hours. Anecdotally, hobbyist mushroom growers and some shiitake growers on the east coast have reported being able to produce mushrooms using municipal water. Nonetheless, some growers may opt to take any risk off the table and let their water sit 24 hours before submerging their logs in municipal water.