In April earlier this year, we brought into the allotment some vegan peat free compost and today — 1st June — we spotted a cluster of three carpophores (fruiting bodies) with cracking pilei (caps) where some of the compost was placed.

A Google image search’s first suggestion is Agrocybe praecox — the Spring Fieldcap — and uploading the first photo to MycoKey’s AI search tool also suggest A. praecox.

They appear to accord with First Nature’s description of Agrocybe praecox.