It got below freezing last night in our garden. Snow flakes were caught on the frost blankets and tarp we used to cover the arugula, beets, kale, and lettuce mix with last night. The greenhouses did their job. We made it through with minimal casualties.
Both greenhouses were effective and prevented young plants from freezing. The wooden/metal greenhouse has leaf matter and compost piled up around the bottom which insulates the structure very well. We watered the insulation and the plants inside to help maintain heat as water is a heat sink. I piled all the empty barrels, bags of leaf and buckets around the hoop greenhouse as a last minute insulation improvment. It seemed to work as nothing appeared to be frozen. Everything inside looks very green and happy.
I picked off a couple small sugar snap peas that were frozen on the inside. I split them open and saw clean white frost inside. It was quite beautiful. The pea plants that were alive all still seem to be. Growth will be slower in the cooler temperatures but production will continue.
Tonight it will not get as cold, and the sun seems to be shining in full force. The same precautions will be taken to protect the plant babies.