What Temperature Do Mushrooms Need to Grow?

Temperature is one of the most critical variables in mushroom cultivation, and it affects colonisation speed, fruiting initiation, and the final quality of your harvest. Getting temperature right, or at least close to right, is the difference between a block that fruits within a week of initiation and one that sits dormant for months or grows slowly and contaminates.

Colonisation Temperature vs. Fruiting Temperature

Almost all mushroom species colonise fastest at temperatures 5 to 10 °C warmer than their ideal fruiting temperature. This temperature drop is a key trigger for pinning. For most wood-loving species, colonisation proceeds best at 22 to 26 °C, while fruiting is initiated and sustained at 15 to 22 °C. Understanding this distinction explains why blocks colonised in a warm cupboard need to be moved to a cooler, more airy space to begin producing mushrooms.

Temperature Ranges by Species

Pearl oyster mushrooms colonise well at 22 to 26 °C and fruit at 15 to 24 °C. Blue oyster mushrooms are the coolest-tolerant, fruiting at 10 to 18 °C and excellent for autumn and winter grows. Pink and yellow oysters need warmth, fruiting best at 20 to 28 °C, and struggle below 18 °C. Shiitake colonises at 21 to 27 °C and fruits at 12 to 18 °C, requiring a distinct cold shock to initiate. Lion's mane colonises at 21 to 24 °C and fruits at 18 to 24 °C, tolerating a narrower range than oysters. Button mushrooms colonise at 22 to 25 °C and require cool fruiting conditions of 14 to 18 °C.

What Happens Outside Optimal Ranges

Colonisation above the optimal range does not just slow growth; it can kill the mycelium or, in extreme cases, trigger fruiting inside the bag at an inappropriate stage. High fruiting temperatures cause small, wiry mushrooms that open and sporulate rapidly. Low temperatures slow everything but typically do not cause failure as long as you remain within a few degrees of the minimum. A reliable thermometer placed where your blocks sit, not mounted on a wall elsewhere, gives you the most useful information about what your mushrooms are actually experiencing.

Practical Temperature Management at Home

Most home environments naturally cycle between a warmer daytime and a cooler night. This daily fluctuation can actually benefit pinning initiation for many species, mimicking the temperature swings that trigger fruiting in nature. If your home runs consistently warm, try moving blocks to a cooler room, a north-facing room, or a cellar for the fruiting phase. In summer, placing blocks in a cool cellar or using a cheap reptile thermostat to regulate a small fan can bring temperatures into range without air conditioning.