greenhouse heating help please

[jayne&tony]

We are thinking of buying an electric greenhouse heater but are not sure which one to go for. A lot of confusion on what wattage??? My greenhouse is 12ft x 10ft and approximately 9ft high.Can anyone help, there is so much info on the net but its all very confusing. Also i live on the isle of wight and what is the optimum temperature i should be aiming for in the winter?? Please help...many thanks

[Alice]

Hello Jayne&Tony. I'm sorry I can't answer all your questions. It depends on what you are trying to do. You ask what is the optimum temperature for winter, but that depends on what you want to grow. You might just want to jeep your greenhouse frost free, or you might want to keep it above 5 degrees, which will give you a viable groung temperature, or you might want to grow more tender plants which need a temperature of 15 degrees.
It all costs money so you have to think about how much you want to spend, and what kind of insulation you have in your greenhouse.
Sorry if this asks more questions than it answers. If you come back with more specific questions I think you will get good answers.

[jayne&tony]

Hi Alice, gosh it all sonds so complicated!!! I presently have Melons and capsicum peppers, chilli's etc still in full fruit and want to try and prolong their life as much as possible. Obviously i know i need to be frost free if i have any sort of chance at acheiving this. We are currently looking at the bio green 2kw expert heater. Its £189, which i am more than happy to pay but wonder what other's think of this one ???Has anyone else used it any views would be great

Thanks

[PAULW]

As Alice said unless you are a commercial grower the cost of heating a greenhouse for a few plants will be uneconomical, what most people seem to do is to work out the area needed to keep the plants you want to keep and make a greenhouse within the greenhouse using bubblewrap and keep this area heated instead of the whole greenhouse

[Alice]

Hello Jayne&Tony. I see you are on the Isle of Wight. You should be able to have your chillies and peppers well ripened before you run into frost problems. As PaulW says make use of bubblewrap and fleece if you have to. Your greenhouse is quite big so you don't need to heat it all for a few plants. You can hang up bubblewrap to create a divider and just heat a section - or make a little tent greenhouse inside the greenhouse or just cover your plants with fleece.
Unless you are going to have your whole greenhouse jammed with plants the cost of heating the whole thing over the winter will not be worthwhile.
I just have a little electric heater which cost about £30 which I use at the end of April into May once I have the greenhouse full. I set it to about 5 degrees overnight just to make sure my plants are OK. Most of the time it never runs as not required. On a run of cold days I put it on just to lift the temperature a degree or two.See what other grapes think.

[Flummery]

I think you have to grow a LOT of veg to recoup your £180 -odds worth of cash, let alone the running costs. I grow in an unheated greenhouse oop north in Yorkshire. With a little judicious taking in at night I manage well with no heat. If I want to grow anything extra tender I would grow it on a windowsill. But they make 'em tight in Yorkshire (says the exiled Lancashire Lass!)

[jayne&tony]

Thankyou all for your advice, much appreciated, will invest in fleece and bubblewrap and see what happens....hears hoping!!

[PercyThrowback]

Hi Jayne&Tony

I was looking at greenhouse heaters when I came across this company. They were featured on Gardeners World and are insulation panels that clip into your greenhouse frame.

I imagine if you packed the insides with bubble wrap it would be really warm.

www.insulitepanels.co.uk

I hope it helps.

[jayne&tony]

Thankyou for that Percy very interesting to read, have you actually tried this product and if so what were the results like??

[PercyThrowback]

I've not tried it, as I only found out about it earlier this year but I saw the article on GW and they raved about it. I was going to try it this year but haven't got round to ordering any yet allthough I probably will if I can find the time. As Flummery points out what ever use has to be cost effective.
Last year Santa bought me a little parasene heater that seemed to do the trick. It just kept the temperature above freesing during the night.

[nick the grief]

a 2kw heater will strugle with a 12x10 grenhouse you need a 3 kw job for that I'm afraid. The Biogreen heaters aren't bad but are expensive as they do 1 that sucks in the warm air from high up, tops the heat up and blows it out of a tube at ground level so it give a more even heat.

If you've got 9ft of head room I would seriously think about putting some bubble wrap at about 6ft-7ft on some wires and cut the head room down ( less to heat & it will insulate a bit better)