Talk to me about your greenhouse heaters

[Bramshott]

Does anyone have a rechargeable battery greenhouse heater which only kicks in when it gets really cold and doesn't cost ££ to run??

Up to now I've put my tender plants like geraniums into the greenhouse and let them take their chances (we're SE but rural). Some years they survive, some years they don't. I'd really like to get a little greenhouse heater to keep the temperature up on cold nights, but a bit scared of paraffin and don't have power. Fan heaters look like they'd cost loads to run, but no tubular heaters seem to come without a lead. Does what I'm looking for exist??

Not really. There are battery space heaters (which get dreadful reviews on Amazon), but wouldn’t be suitable for a greenhouse because of the humidity factor.Greenhouse heaters are designed to be used in humid environments. I certainly wouldn’t recommend paraffin heaters either as they give off a lot of water vapour which is not good in winter.

(I started with a paraffin heater over 40 years ago and it needed to be carefully set each night, to guess how high to set it without it burning out - black soot everywhere! And not more heat than required, plus it was much easier to buy paraffin from the local ironmongers back then) I upgraded to a propane heater which was a bit better and had a basic thermostatic control, but needed gas bottles on a regular basis.

Now, with two large greenhouses I have three electric fan heaters with separate thermostats, to keep temps above 5°c in winter, electric professionally installed by a qualified electrician.

So I haven’t been very helpful, have I? You could try covering plants with newspaper on cold nights which might help a bit, unless you can overwinter them indoors somewhere (spare bedroom?)

Thanks for your reply. In a way it's reassuring to know that there isn't something obvious I'm missing.

I think for this year I will just insulate with bubble wrap and maybe take the plants into the shed on really cold nights (if I remember!).

I read somewhere on here that in France they are much more brutal than us with tender geraniums - they shake the soil off, wrap in newspaper, and keep frost free over winter! I've not tried but you could with a couple, see how they go?

You can get terracotta candle holders like this - or you can make your own from terracotta flower pots. There are various YouTube videos on the subject.

https://www.ksbgarden.com/en-uk/products/candle-heater#:~:text=Description,Candles%20not%20included.