I've been hell-bent on complete self sufficiency for a long time now. There was a point where I was living in a self-sustaining community in the mountains in Colorado, and we had a very large greenhouse there. Dragging the hose around to water plants was a real pain, and that stuck in the back of my mind even after I left the place. It would have been much easier to integrate watering into the frame at construction time than doing that hose dance every day.
After I had time to think about it, and also having acquired some pretty cool pipe bending tools, I came up with this design for a self-watering greenhouse. The one on this video is very small for a few reasons. One, the lady I made this for only wanted a small floating row cover, and two, I wanted to tape the whole process in the shop where I put these things together.
This video's main purpose is to show the basic principles of self-watering greenhouse design. It can be scaled up larger and customized to fit your exact space. You can use these ideas to make the perfect one for your needs.