Let's see inside 2021/22/23/24

I like your greenhouses Veggie! They look so productive I will want you guys to prod me to remind me to sow in the autumn too, so I can test out how far I can push my tunnels here in the winter. That'll be an experiment or two!

This guy doesn't seem to upload anymore, but he grows in the Chicago area, which gets fairly cold,  and shows how one and two layers of cover affects air temperature during winter - https://www.youtube.com/watch?v=VqZn5UBHkjE

I think you can also double skin polytunnels, potentially making three layers of cover if you add smaller hoop houses inside.