Check out bugdorm products. I use their large tents in the lab. These are good, and I believe there is a bottom open model which can be set overtop plants up to 2 feet in height. I do have a sleeve of their's which was only okay. They also sell the fabrics they use.
http://bugdorm.megaview.com.tw/ Kim Cuddington Biology UWaterloo ecotheory.uwaterloo.ca
