A certain amount will depend on what temperature you want to run it at. The higher the more power it will use. That said things like Toms and peppers want about 21C to germinate but as soon as they do you can take it down to about 15. I have a propagator and haven't really noticed an impact on my electricity bill.
That's true for propagators with a thermostat. Many of the smaller ones like the one mentioned above just has an 8w heater that's always on - it will just provide a little warmth. There's a danger of them getting very warm if they're in the sun though.
Billericay - Essex
Knowledge is knowing that a tomato is a fruit. Wisdom is not putting it in a fruit salad.
Love Gardeners forum as it answers most of my questions. There’s a wealth of knowledge out there! I have the seven small propagators on a heating tray and I have had great success with it. Thank you for all the advice
8 Watts is similar to a low-energy light bulb. To run it continuously would be about 0.2 kWh per day, which would be a bit under 7p a day on our current tariff.
Doncaster, South Yorkshire. Soil type: sandy, well-drained
The damp sand also works as a thermal regulator so if the propagator has a thermostat then it will turn off when the temperature is high enough and the sand will retain the heat for longer which means the heater won't need to kick back in for a while which saves energy.
If you can keep your head, while those around you are losing theirs, you may not have grasped the seriousness of the situation.
I use a water retaining fabric in the bottom of my propagators to stop them drying out. It's specially for propagators and I bought replacement fabric in Wilko.
Dordogne and Norfolk. Clay in Dordogne, sandy in Norfolk.
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Many of the smaller ones like the one mentioned above just has an 8w heater that's always on - it will just provide a little warmth.
There's a danger of them getting very warm if they're in the sun though.
Billericay - Essex
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
I have the seven small propagators on a heating tray and I have had great success with it.
Thank you for all the advice