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8 messages
28/08/2013 at 13:23

Relatively new to Gardening but have steadily progressed to a Greenhouse which I bought this summer.   When we get into the winter months is the greenhouse sufficient to shelter the tender plans and seeds from the frost or do I need to get a heater in it and if so what sort? 

28/08/2013 at 16:00

Tender plants will need heat Susan, the temperature in an unheated GH is the same as outside, occasionally colder I've found.

28/08/2013 at 16:27

hi susan I line mine with bubblewrap and am lucky to have electric  so have a small heater set to come on only if it drops to freezing. dont know much about parrafin heaters sorry

28/08/2013 at 22:22

Thank you for your responses

29/08/2013 at 07:41

has anybody got more help for susan

29/08/2013 at 09:34

The 'best' heater would be an electric fan operated one with a thermostat set at 7C with a view of the whole greenhouse staying above 5C. There is no need ot set it above that as the plants do not need it with the amount and duration of light in winter. The fan helps spread the heat around the grenehouse and not at one spot. They are expensive to run but cheaper than buying new plants! Bubble wrap will also help keep the heat in.

I do not have electricity down in my greenhouse and use 2 paraffin heaters. It is a matter of switiching them on and hoping for the best tbh as there is no control.

I find a wooden floor 'warmer' than stone, but if the sun can get to a floor stone then it is possible that the heat is stored in them and released when dark.

If you want to be adventurous then you can try a heat sink system - you will need to google that as it is too complex to explain.

30/08/2013 at 07:47

Thankyou that is very helpful

30/08/2013 at 09:03

I don't have electricity in my greenhouse as it's too far from the house to be economically installed.  I bought a couple of modern paraffin heaters but they were a nightmare - I think the wick kept going out because they poured black smoke out that coated everything including plants.  I was contemplating a gas cylinder heater but the idea of having to lug the cylinder up and down the very steep slope of my garden when it needed refilling was too offputting. So then I bought an ancient Aladdin Paraffin greenhouse heater off ebay (it had been sitting unused in a shed for 30-odd years but there is absolutely no problem getting spare wicks and things via ebay for these oldies but goodies) and it was so wonderful that I bought a second one for my potting shed.  I have a large greenhouse so that one has a 2" wick heater which is a little expensive to run (about £5 a week if on constantly) but the one in the shed is a 1" wick one and, running it about 4 hours a day, I only refilled it twice all winter.  I found that buying a big metal jerrycan and going to a garage for the parrafin was half the price of buying it in B & Q etc.. though you have to hunt around for a garage that sells it. It tends to be small independant old-fashioned garages that still have Paraffin by the pump.  There was a point when I started to wonder whether the cost of heating my plants  through the winter was worth it. I'm still not certain whether it would have been cheaper overall to let the tender plants fend for themselves and just replace any that died in the spring but on the other hand  I managed to grow and keep some more unusual varieties that would have been difficult to replace and I definitely had a head-start on all of my neighbours and had plants in bloom weeks earlier and, overall, a better display all-round so this winter I'm definitely going to do it all again.

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