My log is inoculated but nothing has happened in a year. Is that bad?

It is February, the log has been lying there a year, and absolutely nothing has happened. No mushroom, no fuzz, nothing. We get asked whether it has failed dozens of times every spring. The answer is nearly always reassuring: for most species, a year is simply too early. Below I explain how long it really takes, how to see from the outside whether the mycelium is alive, and when you do give up on a log.

How long before an inoculated log produces mushrooms?

Six to eighteen months is the usual range, and it is that wide because three things play a part: the species, the thickness of the wood and the weather. An oyster mushroom on a thin alder log may show something after six months. Shiitake on a thick oak easily needs eighteen months and sometimes two years. Reishi and maitake are slower still. A log inoculated in March that is doing nothing the following February is simply on schedule.

How do you tell whether the mycelium is still alive?

Look at the cut ends. On a log that is taking, white patches or a white rim appear there over time: mycelium that has grown through the wood and is emerging at the end. The more white, the further along the colonisation. With shiitake that white later turns brown and leathery, which is normal. If after a year there is still nothing at all on the cut ends, that is not yet a bad sign, but it is a reason to look further.

Second check: the plugs themselves. Carefully pick a bit of wax off one hole and look at the plug. White and firm, often with fuzz around it: alive. Grey, shrivelled or loose in a dry hole: that plug has dried out, and if most plugs look like that, the wood has been too dry.

Third check: the weight. Lift the log. A log that is still moist feels heavy and carries on. A log that is much lighter than at inoculation has dried out, and drying out is by far the biggest reason logs do nothing.

What do you do if the log is too dry?

Submerge it. Put the log in a tub or ditch of cold water for 24 hours, or let it soak for a day under a dripping garden hose. Then place it in the shade, ideally with one side on the ground or half buried so it can draw moisture from the soil. Repeat during long dry spells. A log that seemed "dead" often gets going after such a treatment.

Can you give a log a nudge?

Yes, but only if it is colonised. The classic shiitake trick is shocking: soak a fully colonised log in cold water for 24 hours, then stand it upright. The change in temperature and moisture triggers fruiting, usually within one to two weeks. Do this in spring or autumn at temperatures between 10 and 20 degrees, and no more than twice a year, because every flush costs the log reserves. Shocking a log that is only half colonised is pointless: there is nothing to wake up yet.

When do you give up on a log?

When after two years there is no white on the cut ends, the plugs are dry and grey, and other mushrooms have meanwhile started growing from the log. Then a wild species has taken the wood and the race is lost. A log whose bark comes off in large sheets with soft, dark wood underneath is usually finished too. In every other case: leave it, keep it moist, and wait another season. We have had logs that suddenly started in their third year and then produced for years afterwards.

How do you avoid this with your next log?

The three things that matter most: fresh wood no more than six weeks old, inoculating in February or March, and never letting the log sit bone dry for more than a few weeks in its first year. How to judge wood and when to cut it is in our piece on the cutting calendar. And if in doubt, send a photo of the cut ends and we will take a look. Usually we can tell from a photo whether patience is still worthwhile.