Green Pepper failures due to high temp

[GrannieAnnie]

This from the internet which explains why my peppers often don't produce outside and why yours might not under glass if your greenhouse gets too warm:
"Peppers, like tomatoes, are sensitive to temperature. Most peppers will drop their blooms when daytime temperatures get much above 90 degrees F. in combination with night temperatures above 75 degrees F. They will also drop their blooms in the early spring if temperatures remain cool for extended periods. Hot peppers, such as jalapenos, withstand hot weather fairly well and can often produce fruit through the summer in most areas. Optimum temperatures fall between 70 degrees and 80 degrees F. for bell-type peppers and between 70 degrees and 85 degrees F. for hot varieties."

A friend here successfully grows her peppers in the partial shade of a white pine tree which helps keep the heat down while preventing or decreasing I should say, sun scald.

[GrannieAnnie]

[Vinlander]

I grow long bullhorn type sweet peppers and medium chillies, both in a greenhouse and outside.

In SE England it's probably the hottest part of the country in summer if not necessarily the sunniest.

I've never had the greenhouse ones set less than the ones outside - so that confirms what you say about cool.

I've only ever had problems with either location in bad years.

My greenhouse is in full sun until late afternoon with no applied shading- but it does have an automatic vent.

I'd be crazy to have a greenhouse without one.

[GrannieAnnie]

Agree- I'd be crazy to not have an automatic vent here, but I'm always amazed that people are having success with their zippered greenhouses where someone has to be there to vent them daily knowing how quickly the temp can soar in the sun.

[Vinlander]

Agree- I'd be crazy to not have an automatic vent here, but I'm always amazed that people are having success with their zippered greenhouses where someone has to be there to vent them daily knowing how quickly the temp can soar in the sun.

Hmm, good point. Those plastic jobs do get hot - would worry me, but their owners seem to get by without a nervous breakdown.

On the other hand they do get a powerful amount of condensation, so the plants probably get less drying stress.

Also, maybe the droplets are so efficient at scattering that they act like a coat of "cool-glass"?

[BarriedaleNick]

I completely fried my toms last year in one of those plastic zipped jobbies.
I was away for a day or two and then was busy at work so I forgot to open the damned thing.
I think it was the heat together with the 100% humidity - plants couldnt transpire I guess and keeled over.  My mate a couple of doors down cut a flap in the top of hers which keeps it cool but other than that it means opening and shutting everyday...

[Vinlander]

I completely fried my toms last year in one of those plastic zipped jobbies.

I've no intention of using an unvented polytunnel myself, but I'm still wondering if they can work like a bottle garden...

I suppose there's no way to tell the difference between a plant that dried out and one that cooked like  boiled spinach one day and dried the next?

This is the kind of thing that fascinates me - sorry.

Cheers.

[BarriedaleNick]

I suppose there's no way to tell the difference between a plant that dried out and one that cooked like  boiled spinach one day and dried the next?

I guess not but they were well watered and fed!  They all went v limp and then all the leaves dried out and fell off so I assumed they got boiled or just couldn't draw up moisture due to the humidity..

I do have greenhouse envy!  Planning on getting a proper greenhouse later this year after a bit more research (and probably a few questions to the good folks here!)