low tunnels in the greenhouse

Temperature values used are from H. C. Wien's paper
"Use of low tunnels to improve plant growth in high tunnels"

Today we started setting up germination chambers on top of the existing greenhouse benches.  Really our germination chambers are just fancy low tunnels.  Low tunnels are simple hoop structures made from wire or PVC and covered with permeable fabric or plastic.  Their benefits are two-fold for organic and small farmers, they keep insects off plants and warm up the air.  We plan on using the increased temperature to our benefit.

If you put these low tunnels inside a greenhouse or high tunnel (unheated greenhouse) plants are even more insulated from the outside cold.  Our first trials using this arrangement will be looking at the temperature ranges using different materials as covers for the low tunnels.  Permeable fabrics, plastic sheeting and permeable plastic all have their benefits and drawbacks.