Canadian mushroom growing calendar 2026

Mushroom growing in Canada is governed by two things: the temperature of the space you have, and the short outdoor window for log inoculation. This calendar covers both, by region, month by month.

The surprise for most people is that winter is the easy seasonin much of the country, and midsummer is the hard one.

What to do each month, by region, for 2026.

Month	Ontario & southern Quebec	Alberta & Prairies	Coastal BC	Interior & northern BC
January	Best fruiting. Basement 15–19 °C	Chamber fruiting. Ambient RH 10–25%	Outdoor fruiting still possible	Indoor fruiting. Dry air
February	Cut logs (dormant)	Cut logs. Order spawn	Log inoculation begins	Cut logs
March	Cut logs. Order spawn	Order spawn for April	Log inoculation underway	Order spawn
April	Inoculate logs (southwest early)	Prepare. Ground still frozen north	Best month for logs	Inoculate after thaw
May	Inoculate logs (east and north)	Inoculate logs. After last frost	Logs. Fruiting slowing	Inoculate logs
June	Fruiting slows. Move to basement	Good fruiting. Moderate heat	Good fruiting	Heat starts to stall it
July	Hard. Colonise, do not fruit	Fine in a basement. Water logs	Fine. Water if dry	Hard. 35 °C+ indoors
August	Hardest. Contamination peaks	Water logs. Dry spell	Good. Water logs	Hardest. Basement only
September	Second good window. Restart	Good fruiting	Excellent. Logs active	Heat drops. Restart
October	Excellent. Logs active	Move growing indoors	Excellent. Autumn rain	Good fruiting
November	Good indoor fruiting	Enclosed chamber required	Outdoor fruiting continues	Indoor fruiting
December	Excellent. Contamination lowest	Chamber fruiting	Mild. Logs still active	Indoor fruiting

How to read this calendar

Colonise: Mycelium runs through the substrate, in the dark, at 18–24 °C. Possible almost anywhere, year-round.
Fruit: Mushrooms form. Needs the right temperature, 85–95% humidity, and fresh air.
Logs: Outdoor inoculation. One window a year, and it is short.

Temperatures are indicative. Measure your own space — a basement, a garage and an upstairs room in the same house can differ by 8 °C.

Region guides

Each column above has a full guide behind it:

Growing mushrooms in Ontario — why summer is the hard season, and Canada's best hardwood for logs
Growing mushrooms in Alberta — dry air, not cold, is the obstacle
Growing mushrooms in British Columbia — three climates, not one

Questions

When should I inoculate mushroom logs in Canada in 2026?

Coastal BC can start in February. Ontario runs April to May, southwest earliest. Alberta, the Prairies and interior BC wait for the thaw — late April into May. The window closes once trees fully leaf out and the weather turns hot.

What is the worst month to grow mushrooms in Canada?

August in Ontario and interior BC. Indoor temperatures sit above the fruiting range for most species while warm humid air raises contamination pressure. On the Prairies and coastal BC, August is workable — the limiting factor there is keeping logs watered.

Can I grow mushrooms through a Canadian winter?

Yes, and in Ontario winter is the best season. A heated house colonises well and a basement at 15–19 °C is near ideal for fruiting blue oyster, king oyster and shiitake. The one winter constraint is dry indoor air, which an enclosed fruiting chamber solves.

Does this calendar work for Quebec and the Atlantic provinces?

Southern Quebec closely matches the Ontario column. The Atlantic provinces sit between coastal BC and Ontario — milder and damper than Ontario, with a later spring than the BC coast. We publish province guides only where we have query data to support them, so treat those two as the closest match rather than a dedicated column.

Work out your own numbers

Season & space planner — match species to your measured temperature
Fruiting chamber calculator — chamber volume and fresh-air rate
Substrate calculator — recipe amounts and sterilisation time