Mushrooms in Czechia — where do they grow?

The foraging index combines the factors that drive fruiting, weighted toward moisture:

• Soil moisture (0–7 cm, ~30% weight) — the key variable. Mycelium needs water to fruit.
• Trigger — rain 1–2 weeks ago (~22% weight) — fruiting bodies appear ~7–14 days after heavy rain, so we sum precipitation over the −14 to −4 day window.
• Soil temperature (~18% weight) — optimum around 12–18 °C; frozen soil (below ~2 °C) stops growth.
• Recent rain (last 3 days) (~10% weight) — a freshness top-up.
• Air temperature & humidity (~20% weight) — optimum 12–22 °C and ≥ 75%.

We also dampen the index by season (peak Aug–Oct, but never to zero — spring morels, winter oysters) and tune species by forest type (conifer vs broadleaf). Data: ICON-EU and ECMWF via Open-Meteo. This is an estimate from weather and a soil model, not from real sightings.