https://www.youtube.com/watch?v=5TtJ5hNRlik&
We have received our first snow of the year and it is time to begin preparing the greenhouse for winter. We have winter crops planted in the greenhouse and will provide supplemental heat all winter long with a heat sink. This is a bit of an experiment for us, but we expect to be able to grow food all year long with this greenhouse and our traditional soil garden.
Our winter prep consists of adding a second layer of plastic to the sidewalls. The plastic is separated from the existing side wall layer with some lumber. This creates a dead air space between the two layers and provides much better insulation against the cold than that of what a single layer would create.