Protecting young plants from cold

Polytunnels, cold frames, greenhouses, propagators & more. How to get the best out of yours...

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HelenH
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Protecting young plants from cold

Postby HelenH » Thu Apr 23, 2020 8:02 am

I have quite an array of young tomato plants, cucumbers, herbs and courgettes initially started off indoors that have been transferred to my unheated greenhouse. They've all grown on really well but every evening I go through the routine of rigging up various covers and fleece to help protect them from the cold and even bring a few plants back in the house! Is it still too early to dispense with the overnight covers now that the plants are more robust?
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retropants
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Re: Protecting young plants from cold

Postby retropants » Thu Apr 23, 2020 8:43 am

Ideally they need to remain above 10 deg C for optimum growth. I am lucky, as I have a heated propogator, which I switch on in the evening, and off again first thing. Do you have a paraffin heater you could use at night?
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vivienz
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Re: Protecting young plants from cold

Postby vivienz » Thu Apr 23, 2020 9:14 am

I did my heat experiment last night. I brought some bricks and breeze blocks that had been sitting in the sun into the greenhouse and put them on the lower shelf of the staging below the toms. I covered the whole lot in some fleece like fabric (left over house construction materials!) and popped in a thermometer to record it. Inside the arrangement it was 7.5C but 6C outside. For something that cost nothing and only took a few minutes to do, it was worthwhile.
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HelenH
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Re: Protecting young plants from cold

Postby HelenH » Thu Apr 23, 2020 9:16 am

Thanks .... no I don't have a paraffin heater but perhaps I may be able to get hold of one online, if I'm lucky!
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HelenH
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Re: Protecting young plants from cold

Postby HelenH » Thu Apr 23, 2020 11:46 am

vivienz wrote:I did my heat experiment last night. I brought some bricks and breeze blocks that had been sitting in the sun into the greenhouse and put them on the lower shelf of the staging below the toms. I covered the whole lot in some fleece like fabric (left over house construction materials!) and popped in a thermometer to record it. Inside the arrangement it was 7.5C but 6C outside. For something that cost nothing and only took a few minutes to do, it was worthwhile.


Sounds an interesting idea vivienz.
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Re: Protecting young plants from cold

Postby Westi » Thu Apr 23, 2020 8:22 pm

You may as well just continue the routine as it won't be for too much longer. Then you will have time to research some alternative ready for next year. Many a time I have had to wash down of the greenhouse when I had the paraffin heater! On vivienz's experiment I'm saw a set up with tea lights in breeze blocks on some site as I was flicking through the garden sites.
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Vincent_Mara
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Re: Protecting young plants from cold

Postby Vincent_Mara » Tue Jan 05, 2021 10:38 am

excuse me, is this thread still alive? I have a question. I'm new to that forum.
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retropants
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Re: Protecting young plants from cold

Postby retropants » Tue Jan 05, 2021 12:34 pm

sure! We've revived much older threads :)
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Monika
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Re: Protecting young plants from cold

Postby Monika » Tue Jan 05, 2021 2:43 pm

Ask ahead, Vincent_Mara!
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Stephen
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Re: Protecting young plants from cold

Postby Stephen » Tue Jan 05, 2021 7:19 pm

Welcome Vincent_Mara. Every question is welcomed.
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Vincent_Mara
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Re: Protecting young plants from cold

Postby Vincent_Mara » Wed Jan 06, 2021 3:54 pm

How to protect tomatoes from the cold in a homemade greenhouse if it's minus 25 Celsius outside?
I live in Eastern Europe, and it is cold here in winter. I made a greenhouse with my own hands, and I heat it inside with a small boiler. It seems to me that I cannot find an average between good temperature and dry air. Any ideas?
Apologies for my English and my stupid question.
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Westi
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Re: Protecting young plants from cold

Postby Westi » Wed Jan 06, 2021 7:40 pm

I've just had a peek and there are loads on YouTube Vincent_Mara. Also some gardening forum came up from a simple search and it had loads of advice on which candles burn long enough & where together them.

Have fun, some look pretty neat & don't forget to post us a pic and record your temperature differences. Shouldn't be huge I would think but just enough to keep them happier.
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sally wright
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Re: Protecting young plants from cold

Postby sally wright » Wed Jan 06, 2021 10:39 pm

Paint those breeze blocks black and they will absorb more heat during the day time.

I have used candles to heat my greenhouse at home over winter before now. I would use them by putting them on the floor and having the electric heater stationed about two feet above and to one side of them so the flames were not disturbed by the fan inside the heater. This way they supplied the majority of the heat but the electric heater was there for if something went wrong or the candles could not keep up the heat output on a very cold night (or you forgot to light a fresh batch of candles......)

I used home made candles that I designed to burn for 24+ hours at a time; I will not detail the method I used to make these candles in an open forum a very simple reason; I don't want to get sued if some numbnuts messes up. That said, if you can get some really good container/tealight candles for not a lot then you could try those. Put them on a large metal tray or old baking sheet for extra protection and light them on the floor well away from anything that could fall on them and burn. Space them well apart on the tray so that the flames do not interfere with each other as this will shorten their burn time a lot. Most manufacturers do not recommend burning container candles for such long periods and especially not unattended as these would be; so if you want to do this don't blame me if things go wrong.

Realistically this method would be my failsafe those nights for when there is a power cut, blizzard or the fan heater goes phutt and you cannot get to the shops in time. (note to self - get a spare fan heater before spring planting.....) One final thing - tell your neighbours what you are doing so they don't think your greenhouse is on fire.............

To be quite honest I would not think that if you had to go out and buy candles for this idea it would be truly worth it as they are so much more expensive than other forms of heat. For a standard 6 x 8 greenhouse (insulated) you would need at least 4-6 candles per night and that would get expensive if you had to do that for a whole spring season. The only reason I did it was because I had been given mounds of candle ends that I could re-melt and I could re-use the containers and wick sustainers I had (the little metal tab at the bottom of the wick that holds it upright in a container); so the only cost to me was the zinc cored wick. These candle ends were not easy to use for making other good indoor candles so it was a good way for me to use them up.

I really consider that the cost of an electric heater and the electric are just the price you pay for a greenhouse full of plants that are the varieties YOU want rather than having to take what plants the garden centre thinks you might like. It still works out much cheaper than the same amount of plants from a garden centre.

Regards Sally Wright.
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Stephen
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Re: Protecting young plants from cold

Postby Stephen » Sat Jan 09, 2021 11:00 pm

Apologies for my English and my stupid question.

Your English is fine & no question is stupid.

minus 25C is certainly cold. Making the most of whatever solar heat, as Sally says, is a good start.
Making sure there is minimal loss to the exterior is next.
Then add some heat, I'm trying to think about what would be cheap and create only just enough heat. Night storage heaters are probably the way to go.
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Pyshop
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Re: Protecting young plants from cold

Postby Pyshop » Tue Mar 23, 2021 12:29 pm

Trying to explain Cloches to the kids, Why don't you give them Mexican hats was the reply ?
How will I do that then,
Like this ? putting the plastic tops from Walls ice creams, Good idea or just an excuse to get more ice cream.
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