Commercial greenhouses often have roll-up sides, which are available from suppliers like Grower's Solution ($67.00 for an 8-foot side), or you can DIY a basic version with PVC pipe. I made one ...

According to @mamabeartalk8, building a DIY greenhouse doesn't have to be difficult. In fact, you only need a few materials ...

Greenhouses are a great way to improve conditions ... constructed out of short lengths of Schedule 80 PVC pipe. The struts are attached to the pipe with steel straps, screwed into place.