Heating greenhouses (polycarbonate)

[cheshirepalms]

I purchased a greenhouse last October, and overwinted some small palms,an olive, some citrus, some figs, some pomegranates and a musa bajoo,which all survived (well i had to bring the citrus in on frosty nights) i am now using it for tomatoes and cucumbers and rearing seedlings. However i would like to overwinter frost tender plants all winter like the citrus and any new additions. My minimum in the greenhouse last winter was -5.6 which i think is low for a relatively mild winter in a semi coastal environment under shelter. Is it safe to run a electric greenhouse house heater from my kitchen to the greenhouse with just a circuit breaker? I am thinking a minimum of around 5 degrees. Any thoughts would be great

[Tom2006]

Yes it certainly is. Get a good one thought that is drip safe and turns itself off if it topples over. I used one like this to heat my poly house in the winter just gone and it worked an absolute treat!

[cheshirepalms]

So no additional or weatherproof wiring running from the house to the greenhouse?

[Tom2006]

I just plugged the heater into my power source in my shed and put the heater in my poly house and job was sorted

[jungle jas]

I purchased a greenhouse last October, and overwintered some small palms,an olive, some citrus, some figs, some pomegranates and a musa bajoo,which all survived (well i had to bring the citrus in on frosty nights) i am now using it for tomatoes and cucumbers and rearing seedlings. However i would like to overwinter frost tender plants all winter like the citrus and any new additions. My minimum in the greenhouse last winter was -5.6 which i think is low for a relatively mild winter in a semi coastal environment under shelter. Is it safe to run a electric greenhouse house heater from my kitchen to the greenhouse with just a circuit breaker? I am thinking a minimum of around 5 degrees. Any thoughts would be great

Don't wast the space on Pomegranates they are as tough as old boots. Mine have been frozen solid in pots for the last three winters. Still looking good.

[cheshirepalms]

I have 3 pomegranate seedlings which ive grown from seed last summer, they're only 6 inches tall, will they be ok unprotected for winter?

[maritimesbob]

Yep, I rigged up a small fan heater in my poly greenhouse. Lowest temperature was about 8C and the heater wasn't on all that much, my electric bill barely changed with this one. I kept the fan on quite a lot to keep the air moving and prevent rot.

I purchased some outdoor cable, a waterproof socket and a breaker. The whole thing including heater cost me about £25!

I did bubble-wrap the interior in December, just in case.

[MonkeyDavid]

If you can line the inside with bubble wrap for the winter it will make a HUGE difference to the temps & the amount of time the heater has to be on

[JBALLY]

I heat my 10x12 greenhouse every year with a 3kw heater to 10 degree centigrade.For three years a heavy duty extension cable and circuit breaker ran from my kitchen is what powered it and a light and three large propagators. The wire was thicker than a normal extension lead but was not armoured until I sunk it in the ground and ran it through a protective plastic conduit earlier this year.I do bubble wrap my greenhouse which helps a lot in reducing the cost as the first year it was not bubble wrapped and it cost a lot. I find a fan heater that just comes on when the heater comes on rather than running a fan continuously is enough to keep my plants healthy. I keep sixteen different varieties of citrus in their as well as not so hardy palms, bannanas and a whole lot more.I am lucky though as I have a unheated greenhouse for my slightly hardier plants aswell.

[cheshirepalms]

Thanks guys i'm off to b n q on monday as there is 20% off this weekend to get armored cable a circuit breaker, a heater and bubble wrap for the winter.