Heating my new little greenhouse - electricity?

I have almost finished constructing my 6x8 Rhino Greenhouse and I was planning to add electric tube heaters (I have power nearby) until I saw some alarming numbers for running costs. I'm planning to overwinter some cuttings and perhaps start seedlings a little earlier.

I guess I'm just trying to prevent a frost - is it worth trying and can it be really expensive?

 

I keep two greenhouses, one same size as yours and one a bit bigger, frost free with fan heaters, Not tried tubular heaters but they are slow to react and don't spread the heat evenly IMO.

 

I know I am in Cornwall and we don't get many frosts (though we still get some) but I find light is more important than heat in my greenhouse and also ventilation. I probably lose more things from damp than cold. Fan heaters would have the advantage of keeping the air moving and drier. When a frost is forecast I cover everything up with fleece and bring the most precious things inside.

 

I'm not sure a heater is likely to be much use with starting seed earlier, if you are only going to keep the frost out with it.
Might be better investing in a propagating bench if that is the aim.

Heating a greenhouse to seedling level can be very expensive early in the year, come something like april and it gets cheaper and more realistic.

 

Think you need to look at either insulating your greenhouse or building something like a small frame and heating just that smaller area.

A fan heater in a small frame would be too big, heat wise, so a tubular heater with a small fan is better to ensure the air is distributed around the plants etc.
We use this method for our Orchids and also use it to overwinter a few other plants /cuttings.

For starting off seeds and cuttings those seed tray sized heated proagators are good.

Both methods ideally need to be thermostically controlled as even in winter the sun can easily overheat things.

 

If a propogater is not in the budget, you can simply tape up a piece of plastic to create a partitioning curtain and have a smaller space to heat. And keeping the air circulating will help.

I have no idea what a tube heater is but you may not need to push your electricity bill to heat the entire cubic footage.

I have the luxury of a natural gas heater which is fueled from mains supply but I still couldn’t carry the expense of turning my 6x8 greenhouse into a "hot house".

 

It would really depend on what you intend sowing/growing @Soundof trains , and also where you are for putting them outside in spring etc.
I've never bothered with extra heat for anything, because they'd just have to stay in warmer conditions for much longer anyway before putting them outside, and that can be tricky getting enough room for them once potted on. A mild winter for us is still upwards of 40 odd frosts.
My house isn't particularly hot now either in late winter/early spring, because we've got used to the heating being on less due to the cost!

 

Don't think you have them in Canada, they are enclosed low wattage heaters, ideal for keeping frost out of a small area, available in sizes from 1 ft to 6ft with about 30 to 60w of heat per foot length, some have a simple thermostat built in.

 

Thanks everyone for all the responses. I think I will make sure I have the trunking for power under the foundations, but hold off for the moment and see how I use it this winter. I had a large polytunnel before which is a different thing altogether.
@ricky101 your frame looks great btw. I do have a heat mat and propogator that I use for starting seeds, but perhaps a thermostat controlled one might be helpful too.

 

There are good quality plug and play greenhouse thermostats from Inkbird like their ITC 306/8/10 range or if you are competent with mains you can get the cheaper ITC 1000 though clearly you need a proper electrical housing etc for greenhouse use.
There are cheaper clones on the usual sites but would be weary about their use in a greenhouse.
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