Sounds good ! Thanks !You can just use some cheap painters plastic. If you hang them close together, it keeps the humidity up around the plants too. But I really don't think you have much to worry about hanging whole plants at that temp and humidity if that is your day time average. The stalks feed a lot of water into the leaves. I hang Harrow Velvet in dryer conditions that you have and never have had a problem with it coloring. Now if you were hanging stings it would be different and I would try to keep the humidity at 70% or more until it yellows.