Heating

Heating for tents and propagators through cold nights

UK grow rooms lose heat fast once the lights switch off, and a cold snap overnight can drop veg temperatures below where roots want to work. A 45W propagation heat mat (from £29.95) sits under trays of cuttings or seedlings and lifts medium temperature by a few degrees — the difference between clones rooting in a week and clones sulking for two. Pair it with a thermostat if you're propagating through winter, since a mat left running flat out can cook a tray of rockwool cubes dry.

For the wider room, a Lighthouse 2KW grow room heater (£39.95) with its own thermostat holds ambient temperature in an unheated space, while Hailea water heaters (from £14.95) go into reservoirs and tanks to keep root-zone water warm — cold feed water is an underrated cause of slow uptake in winter hydro setups. Tube heaters are also worth considering for tents where a fan heater's airflow would disturb the canopy.

Getting the target right

Seedlings and cuttings want 22–26°C, established plants in veg 24–28°C — see the full stage-by-stage table in our grow tent setup guide. Overheating a propagator is as common a mistake as underheating one, so always run a heat mat through a thermostat rather than straight to the mains. Free UK delivery over £50, next-day available on most heaters.