Here is a link to what you need. These are fast easy and inexpensive. |
Here is a link that might be useful: Insulation clips
Or you can do like many of like many of us here and throw a clear, solar pool cover over your greenhouse in the winter. I put one on my 10x16 glass house this winter and it worked very well as extra insulation. I took it off a couple weeks ago. The Ultra Therm covers are clear, from Americas Best Pool Supply. |
Here is a link that might be useful: Ultra Therm Pool Covers