An open or closed question...

Hi Everyone,
I have two small polytunnels planted up with winter stuff like Texel greens, lettuce, pak choi etc. My preference would be to leave the doors open all winter - good or bad idea? Will it make much difference?
Thanks
Jen

 

They are the double zip type doors a proper pain in the derriere....so laziness I suppose .

 

I would open the doors on sunny days and ventilate on mild days too. If it's frosty or windy, keep them closed.

 

WHen I had a greenhouse, I used to do exactly this. I used to house my semi tender plants in the greenhouse over winter and by keeping it open during the milder weather, they become more tolerant of the colder weather.

 

Since asking the question the weather has turned decidedly summer like - into the 20s some days so I've yet to close the doors. Everything growing away nicely apart from the potatoes which have yet to make an appearance.

 

Regarding winds, I have doors at each end and leave the ones at the rear facing East open most of the time to keep it ventilated and avoid conditions favourable to botrytis, only opening the West facing door in summer but not when there's strong westerly winds that could shake then cover to bits if they got inside, and there's been a lot of those recently.

As for temperatures, I've got two USB temperature data loggers, have put one inside a tunnel and the other outside, and when it gets very cold there's not been very much difference overnight/early hours between in and out temps, especially in small tunnels, but I'll re-do that test over winter.

 

@Scrungee would be interested in your results. I recently read a study that reported inside the polytunnel was colder than outside when temperatures were very low. My doors are still wide open and stuff growing away nicely...still no sign of the tatoes though...

 

I have a very nice crop of conservatory plants in my polytunnel, just have to hope the planners have a good xmas. Then I can plant out the blighters, and er in doors can sit and enjoy the view .