Hi Charles
I see that your June 13th poly tunnel photo shows closed polythene doors with little ventilation. Was this taken at the crack of dawn (while most of us still have a couple of hours left asleep!) before opening up for the day?
With those of us who cannot get to the plot every day are we better having open doors/debris netting doors rather than polythene doors from now on, particularly in this hot spell? I also have the option of a polythene half panel below and a debris netting half panel above on my 4′ doors, as well as a permanent 6″ gap above the doors.