The warmest summer since 1901: what it did to your mushroom logs, and what you can still save

The Dutch meteorological institute KNMI has now made it official: with an average temperature of 19.3 degrees, summer 2026 was the warmest since records began in 1901, with 776 hours of sunshine nationally against a normal 641, and on only three days did more than 50 millimetres of rain fall anywhere in the country. By late August the rainfall deficit stood around 285 millimetres, well over two and a half times normal, and above 300 in the south and west. Much of north-west Europe saw the same pattern. If you spent the summer on a terrace, that was lovely. If you have logs lying in the garden, it was three months of holding your breath. Here is what a summer like that does to mushroom logs, how to see now what is left of yours, and what you can still do in September.

What does a summer like this do to a log?

Two things at once, both covered in our weather piece: drying and heat. A log that gets no rain for weeks loses its moisture from the outside in, and the mycelium just beneath the bark dies there first. A log lying in the sun on top of that gets warmer inside than the thirty degrees at which most of our species shut down. The combination is the worst there is. Logs inoculated this spring had it hardest: their mycelium was still shallow and had no reserves. Logs two years or older, with a network deep in the wood, mostly sat out the summer in standby.

How to assess your logs now

Take an afternoon and go through them one by one. Four checks, the same as in the piece on a log doing nothing, but now with summer as the suspect.

• Weight. Lift the log. If it feels much lighter than at inoculation, it has dried out. That can be fixed, see below.
• Cut ends. White mycelium on the cut end is good news; the network is alive. Grey, hard and without white: undecided. Black streaks or foreign mould patches: the competition has struck.
• Plugs. Prise one plug out. White and firm: alive. Grey and shrivelled in a dry hole: dead, and if most look like that, the log probably is too.
• Bark. If the bark is still tight, the wood inside is probably still fine. If it comes away in sheets, the log is too far gone.

Dried out but alive: how to recover it

Soak it, longer than you think. A log that has dried for a whole summer does not take up enough in one night. Put it in a tub, trough or ditch for 24 to 48 hours with a weight on top, or run a dripping hose over the pile for two days. Then lay the logs in the shade with one side on the ground and cover them with a thick layer of leaves or wood chips. Repeat the soak after two weeks if the weather stays dry. Mycelium that sat deeper in the wood often grows back outward within a month, visible as fresh white patches on the cut ends. A flush this autumn is not out of the question, but count mainly on next spring.

What we saw at the nursery

The same as everyone, with one difference: our logs lie close together in the shade and were kept under a layer of chips all summer, and nearly all of them came through well. The phoenix oyster, our summer species, even gave a flush in July while the common oyster next to it did nothing. The wood chip beds had it hardest: a bed that was not watered weekly stalled in July, and the best beds are those under dense planting. Indoor grow kits did what we predicted in the summer piece: the pink and golden oysters thrived, the rest waited in the fridge.

And if a log did not make it?

Then September is the month to accept it and look ahead. A dead log is firewood or ground cover. The good news is that the calendar helps: pruning season is coming, fresh wood becomes available, and in February you can inoculate again, as in the cutting calendar. Anyone who lost a log has at least learned where the real shade in their garden is, and that is exactly the knowledge the next log needs.

What we will do differently

If summers like this become the new normal, and KNMI says this pattern fits the changing climate, outdoor growing shifts. More logs half buried instead of laid loose. More cover with chips and leaves, all year round. More phoenix oyster and less common oyster on logs that might catch sun. And watering earlier in the season, not only once the log feels light. None of these are big changes, but they are the changes that this year made the difference between a log that lives and one that no longer does.

Unsure about a log? Send us a photo of the cut ends and a plug and we will take a look. We are busy with exactly that these weeks, and that is fine: it is what a nursery is for.