Topic: When to open a polytunnel?

[vjm63]

Hi all,

I know this is a ridiculously basic question but I would appreciate advice!

I have got a polytunnel this year for the first time but I do not know know when I should be opening and closing the vents/door!  There are vents near the top of both ends and a full door in the southern end. I have got a max/min thermometer in there which has shown me it gets to single figures in the nights still last month but it rapidly seems to get up to 30 during the day if there is even partial sun and cloud.   It is in a slightly shady area so does not get full sun (if available) until maybe 9am now and then is into shade from other things by 8pm at the moment. It is in the veg patch next to the house so it is not a half hour trip to open and close - but I do not want to be diving in and out all the time not knowing what I am doing, if you see what I mean...

What sort of vent and/or door opening habits to others have for their polytunnels? Any suggestions would be appreciated because at the moment I do not have a routine or guidelines and think that I am not making best use of it.

Thanks for being patient with such a daft question!

[manicscousers]

We have a 30x10 tunnel and we have had both end doors open for the last monthas ours is on the plot, 15 mins away by car.
ray has made mesh doors for both ends to keep the birds/cats out so we just shut them. It's up to 95 in there some days . The stuff grows a little slower but doesn't fry 

[vjm63]

Thanks very much for that.

Sounds like leaving the vents open all the time should be ok then. I must admit I was worried about the high temperatures - especially after a fig tree I have in a pot in there started to get yellowed then falling off leaves  (The thermometer got up to 40 that one day). That has stopped and it seems ok now (I hope).

[Nomspatch]

My tunnel, has been mostly 'open', like manic scousers I have screenmeshing on the doors, since the fear of frosts (hard ones) passed...I close it up if it turns chilly in the day (mines in the garden too) to get the heat up a little for the overnight temp to be a little better. The min/max temp guage is vital in my opinion, I try to keep the tunnel between 60 and 80 in the day, which has resulted in having shade netting and shading blinds put on, they are staying on now as well because the plants all seem MUCH happier with their environment and the ground isn't drying out so fast.
Mine is in full sun all day (when there is any) and temps have rocketed off the scale on one or two days where I haven't opened enough vents...
It looks like this...26x12ft
http://nomspatch.blogspot.co.uk/p/the-polytunnel.html
shading looks like this...
http://nomspatch.blogspot.co.uk/2013/06/blazing-junewell-it-was.html
I hope this helps a little, though I admit I am still learning how to manage it properly (its been up for 4yrs now (ish) terrible memory for dates me!) but I couldn't imagine being without it now...