Beech Tarcrust Care (Biscogniauxia nummularia)

This fungus develops naturally on beech wood in shaded to semi-shaded forest conditions with limited direct sun exposure.

• Provide bright shade or dappled woodland light, such as under a beech canopy, with no more than 1–2 hours of weak morning sun and no harsh afternoon sun.
• Avoid full, open exposure; strong midday sun can overheat the substrate and dry the host wood, reducing the stability of Beech Tarcrust colonies.
• Seasonal shifts are tolerated, but prolonged deep shade under dense summer foliage slows fruiting, while moderate winter light on bare branches is usually acceptable.

This wood-inhabiting fungus relies on the natural moisture balance of beech trunks or fallen branches rather than direct watering.

• Select well-drained but moisture-retentive beech wood; it should feel firm and slightly damp, not soggy or crumbling, before introducing or expecting Biscogniauxia nummularia.
• If cultivating outdoors, allow rainfall to supply most moisture; intervene only during prolonged drought with light, infrequent wetting that moistens the wood surface without leaving standing water.
• Signs of excess moisture include soft, rotting wood and sour smell, while very dry, cracking wood indicates underwatering; adjust exposure, not constant soaking, to correct either condition.

This species is adapted to temperate woodland climates with cool to mild conditions across the year.

• Aim for a general range of 40–75°F (4–24°C), where growth and fruiting bodies remain most stable on living or dead beech wood.
• Short cold spells down to about 20–25°F (-6 to -4°C) are usually tolerated on outdoor substrates, but repeated freeze–thaw with intense sun can damage exposed wood surfaces.
• Sustained heat above 80–86°F (27–30°C), especially with dry air, can desiccate the substrate; partial shade and leaf litter help buffer temperature and moisture through hot periods.

Humidity is not a key factor for Biscogniauxia nummularia, which typically develops on outdoor beech wood in ambient conditions.

This fungus develops naturally on dead or stressed beech wood rather than in conventional soil, so soil preparation focuses on recreating suitable woody substrate conditions.

• Use well-decayed beech logs or branches with intact bark instead of any potting mix or mineral soil.
• Ensure the wood remains moderately moist but not submerged, avoiding standing water around the substrate to prevent anaerobic conditions.
• Position the wood in a shaded, humid outdoor spot where air still circulates, limiting direct sun that would over-dry the surface.
• Avoid chemical treatments, paints, or preservatives on the wood, as these can inhibit colonization and fruiting of Biscogniauxia nummularia.

This species is not suitable for conventional container growing, as it is a wood-decay fungus dependent on beech timber rather than potting media.

This fungus lives on beech wood and does not need fertilization in typical woodland or log-culture conditions.

Pruning is not applicable for Biscogniauxia nummularia, since it is a wood-inhabiting fungus rather than a managed garden plant.

Transplanting focuses on moving colonized wood rather than handling the fungus as a potted plant.

• Select beech logs or branches already colonized, showing characteristic black crust on dead or dying wood.
• If relocation is needed, move wood during cool, moist weather in spring or fall to reduce drying stress.
• Place the colonized wood in a shaded, humid spot to mimic natural woodland conditions.
• Avoid cutting or stripping bark excessively, since this damages the habitat the fungus requires.

Propagation for this species is not normally attempted in home or garden settings because it spreads naturally via spores on suitable beech wood.

No special winter care is required, as this fungus is adapted to temperate outdoor conditions on dead beech wood.