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Magic Mushroom Grow Kit Temperature: Keeping Your Kit Warm in Winter
The right magic mushroom grow kit temperature is a steady 23 to 25 °C, and never above 27 °C, according to the Mondo grow kit manual. In winter many living rooms average 18 to 20 °C and cool down further at night, which slows pinning or stops it. The fix is usually a better spot plus gentle bottom heat, not a hotter room.
What temperature does a magic mushroom grow kit need?
A Mondo grow kit needs 23 to 25 °C during fruiting. Stability matters as much as the number: a kit that sits at 24 °C all day and drops to 17 °C at night behaves more like a cold kit than a warm one.
| Temperature on the kit | What usually happens |
|---|---|
| Below 20 °C | Pinning slows down or stops; flushes take much longer |
| 20 to 22 °C | Growth continues, but expect a slower first flush |
| 23 to 25 °C | Ideal range from the Mondo manual |
| 26 to 27 °C | Still within the limit; check the kit more often |
| Above 27 °C | Outside the recommended range; risk of heat stress and bacterial problems |
Where should you place a grow kit in a cold house?
Place the kit in the warmest room that stays warm at night, at table height, away from windows and outer walls. Warm air rises, so a shelf at chest height is often a degree or two warmer than the floor.
Good spots in winter:
- an inner wall in the living room, not next to the radiator;
- a kitchen cupboard top, away from the oven;
- a room with underfloor heating, with the kit on a shelf rather than directly on the floor.
Spots to avoid: the windowsill (cold at night and too much direct light during the day), directly on or above a radiator, near an outside door and in an unheated bedroom.
Measure on the kit, not on the thermostat
The thermostat measures the air at one point in the house. Stick a thermometer strip to the side of the container or bag and read it in the morning, when the room is coldest. That number tells you if you need extra heat.
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How do you use a heat mat safely?
Use a heat mat with a heat guard between the mat and the kit, and start at the lowest setting. A heat mat placed directly under a kit can create a hot spot in the bottom of the substrate while the top stays cool.
The heat mat and heat guard guide explains the set in more detail.
Never cover a heat mat
Do not put towels, boxes or blankets over a kit on a heat mat. Trapped heat builds up quickly and can raise the temperature far above 27 °C.
Does cold harm a grow kit permanently?
A few cold days rarely kill a healthy, colonized kit; they mostly slow it down. The mycelium becomes less active and pins form later or stay small. When the kit warms up again, growth usually resumes.
Prolonged cold is a different story. Weeks at 15 to 18 °C mean the kit spends much longer in a humid bag before it fruits, which gives mold more time to get a foothold. If your kit has shown no change for a week in a cold room, warm it up before you conclude something is wrong. Our article on a grow kit that is not fruiting goes through the other causes.
Should you change anything else in winter?
Mostly, no. Keep the routine from the manual and change only the temperature. Light, humidity and fresh air stay as described in our guide to fruiting conditions. Two winter-specific points:
- Air exchange: central heating makes room air dry. When you open the bag to exchange air after pins appear, keep it brief so the inside does not dry out.
- Delivery: in freezing weather, unpack the kit as soon as it arrives. Do not leave the parcel on a cold doorstep or in an unheated hallway.
For a fully controlled setup, a grow box with a heat mat and an LED light takes the room out of the equation. That is useful in houses where the temperature varies a lot between day and night.
Keep your kit warm with Mondo
Every Mondo product comes with a step-by-step manual on our site, and orders ship discreetly with tracking.
View the heat matQuestions about grow kit temperature in winter
No. A radiator surface is far hotter than 27 °C and switches on and off, which gives big temperature swings. Use a heat mat with a heat guard instead.
It is below the ideal range, but the kit will usually still grow, only more slowly. Expect the first flush to take longer than the 2 to 4 weeks given in the manual.
Usually not. If the room is above 22 °C day and night, switch the mat off and check that the kit does not go above 27 °C.
Gentle bottom heat at the right setting does not, because the filter bag holds the humidity. A mat set too high can. That is why you start low and measure.
The soaking step in the manual is done in the fridge on purpose. That short cold period is part of the routine and does not harm the kit.
