Here's a close up view of the rolled up sides, looking in on the potatoes and tomatoes. Bill says the sides will pretty much stay up through August, now that the weather is consistently warm. Obviously, this set up prevents the high tunnel from overheating. It also provides access for naturally beneficial insects.
Our roll up system is pretty simple. The plastic is just wrapped around one long pole. The pole has a t-joint at one end with another pole inside. That side pole is resting on the ground, so we can pick it up, use it to rotate the roller-pole, and then stick it back in the ground to hold the roller up.
The sides are up pretty high right now, but we could further regulate the temperature by raising or lowering the sides throughout the season (over even the day).
Check out these roll up photos from Rutgers