Ideal minimum overnight greenhouse temperature

[ghexton]

Hello All,

What is the IDEAL minimum overnight greenhouse temperatures?

I have in the GH chillies, toms, cucumbers, melons, sunflowers and lots of other more hardy veg. ive run out patience and space in the house so that is where they will stay.

I currently operating a small home heater in the GH (https://www.dimplex.co.uk/product/glofan-heater) which isn't designed for the job really, i have the thermostat set to 15/16c and the minimum in the GH was 10.5 last night so its not doing great but also not doing terrible. With cold snap around the corner, im wondering if it is worth getting the proper GH one with thermostat. But what is the IDEAL minimum overnight greenhouse temperatures?

I've read 10c for tomatoes, is it the same for chillies? Or should i be looking around 16c?
I have chillies potted up on the floor would these be warmer higher up on the racking?
Im just a little cautions you see, wanting to keep the plants cared for.

Thanks all
GH

[Stan79]

Fleece would be cheaper than running a heater in a greenhosue!

[ameno]

It's 10c for all of them, basically.
Although "ideal" and "minimum" is a bit of a contradiction in terms, seeing as ideally it should be warmer than that, as they would grow faster if it were. But at 10c or above, you shouldn't see any cold-relate checks in growth like you would if it frequently dropped much below 10c.

And whether it's warmer higher up or lower down depends on a number of factors. Yes, cold air sinks, but also if you have ventilation open at night then it is likely to be draftier higher up, and also if the floor is solid (concrete, slabs, bricks, even compacted earth) they it will absorb heat during the day then give it back off during the night, warming the air near it.

[ghexton]

Thanks Ameno, i will try and aim for around 12c. Ive the heater set the 16 but is i guess struggle to remain at that.

[burnie]

I use fleece, not ideal but gives some frost protection, single glazed glasshouses will just haemorrhage heat, whatever you set a heater at, so I use a plastic "blowaway" to protect things like chillies and cucumbers. Having said that most of my chillies are still in the double glazed conservatory.

[burnie]

Just checked, my overnight minimum was 5.9 last night, it is now 15.6 so I have removed the fleece from the tomatoes and dwarf French beans.

[Bren In Pots]

Last night my was 11.6c but tonight its supposed to so down to 3c according to the Met office.